Site Update: 2.5M Views, Holiday Plans & Optical Disc Corner

The site’s been pretty quiet as compared to how it was before the start of the year. I didn’t expect it to get this way, but it did, for better or for worse. The first major leg of my holiday went smoothly, and I had a great time. I returned to Sydney for about three months to take a breather, attend a few events, process some photos and get ready for my next adventure. This post will be a bit of an update on how I’m going, and what’s happening in the future.

Milestone: 2.5 million views!

First thing’s first – a little bit of patting myself on the back. As of writing this post, we just ticked over 2.5 million views since the site launched at on the 25th January 2013. That’s a lot more views than I expected, although there is a precipitous drop in visitor numbers at the beginning of the year since I started my holidays and was on blogging hiatus. Will the numbers recover? Maybe not. But I’ve still got more than the 7-views-a-day I started with, and that makes me happy to see.

This is the list of posts with more than 20,000 views. No surprise, the home page sits at the top, but the posts on the list all have their own “appeal” in a way. This list alone accounts for 35% of the total views. The bandwidth consumption is still a staggering 390GB a month, which is a lot of data for a personal blog.

Holiday 1.0: Hong Kong, Taiwan and South Korea

After completing my PhD, I promised myself to spend this year on vacation to recharge myself and immerse myself in more culture. It was a necessary sea-change, and the first set of trips was to Hong Kong, Taiwan and South Korea spanning 30th January 2017 through to 12th April 2017.

Needless to say, that is all over now but it was a marathon effort that went surprisingly well. I took about 18,000 photos, carried home about 7TB of data including various recordings of radio and TV broadcasts; and didn’t end up losing anything even though I had feared I did. I did manage to damage one of my lenses, so I ended up buying a replacement. I also ended up buying a few Xiaomi products which are part of my day-to-day arsenal, and that’s been quite good.

Hong Kong Geopark: High Island Reservoir – East Dam, Hexagonal Columns

While on holiday in Hong Kong, I stayed with my relatives and found my way around with relative ease. Travelling in Taiwan was also with family and by a one-week round-the-country tour, which didn’t require much initiative on my behalf.

QingJing Veterans Farm, Nantou, Taiwan

When I got to South Korea, I was on my own for the first time, and I enjoyed it immensely. I chose the self-directed tour route – I decided what I wanted to do with each day, and I felt free to let myself get distracted along the way. I found many times where I would wake up wanting to go to a few destinations, but had somehow been diverted along the way by a sign to something even more interesting that I didn’t have any idea of.

Food stalls inside GwangJang Market, Seoul

I felt safe, despite the protests in the capital at the time, and even though there were a few instances of a language barrier, I could cope for the most part. Due to convenience, I spent a lot of time eating fast food (which, in itself, is quite interesting to see the regional variations) but due to the vast amount of walking (3-4 hours a day) and a meal-skipping regime, I even lost 6kg (which has since been put-back-on since I returned home). With the good connectivity (for the most part), I was not far from digital help even though Google Maps was hilariously wrong in places.

Seoul City Wall

But the biggest surprise to me was just how adaptive I was – in a place completely devoid of test equipment, on a small and limited laptop screen, in a room in a different country, no longer blogging on a regular basis I had absolutely no feelings of missing home or my elaborate set-up in my room or even my old day-to-day schedule. I felt liberated in a way, that I could find happiness in entirely different pursuits I had never had the time to pursue in the past.

View of Seoul from Naksan Park

South Korea feels very much like a homely place to me now, after spending about 6.5 weeks there and knowing some of their culture from TV and learning bits and pieces from visiting museums. Every country has their own differences – they seem to be very much prepared for any situation, but they also have an obsession with numbers which means that engineers can delight in knowing everything about their infrastructure and facilities without having to ask! I had the time to ride on every single subway line in the country except one. I also rode the full length of the Busan, Daejeon and Daegu subway systems, and delighted in riding their driverless lines (of various different technologies) especially.

A couple in Hanbok, under sodium street light in Insa-dong, Seoul

After my return, I had a bit of a holiday hangover – I was confused about which side of the road to walk on, I looked the wrong way for oncoming traffic, etc. But for once, I felt less safe about riding the public transport at home compared to when I was overseas. It’s odd to feel like a stranger in your own hometown. But at least I knew where everything was, and how to get around …

Sunrise from the plane, on the way into Sydney

I spent a good slice of my time processing my photos and compiling a large photobook to celebrate. In-between that and planning the next holiday, getting into vinyl records, attending events, doing the odd review, updating and maintaining the computers at home, peer-reviewing papers and fixing up a few publications for the uni, my three months had disappeared leaving no time to actually post the photos online along with their story. I hope to do it sometime in the future, even if it does come very late as I did see and document some rather interesting things (at least, in my opinion).

Holiday 2.0: Singapore, Japan and Hong Kong (Redux)

My coarse plan for the year had me touring Australia in between my overseas trips. Once I saw how much it cost for domestic airfares and accommodation, I seriously reconsidered the plan. If it costs me about the same to tour overseas, I would obviously prefer that. Through good timing and a choice of dates that landed my flights with budget carriers (Scoot, Tiger, Jetstar), I set the plan to visit Singapore, Japan (Tokyo, Kyoto, Osaka) and Hong Kong (since it’s on the way in a way). All of these are countries I had wanted to visit for one reason or another, although given the North Korean situation, I’m hoping there won’t be any trouble in the meantime.

In fact, it’s coming up so soon that I’ll be flying out on Wednesday. Expect a lengthy silence from then – but if you’re in Singapore, Japan or Hong Kong and want to meet, give me a shout.

The Optical Disc Corner

But before I leave, I’ve got a present for all my readers. I spent a few days hunched in front of the computer and a scanner to bring you The Optical Disc Corner, which is similar to the CPU corner, and the VHS corner. This shows you the retail-print/packaged recordable/rewritable optical discs I still have. Unfortunately, many years back, I did throw out many of the earlier examples I owned (e.g. HiCo, Pyrod, Princo, etc.) so it’s only a shadow of what I once had, but it still comprises over 400 scans. I just hope no companies have any objections to its posting.

There are many discs I know of, but don’t have, so if you have anything particularly interesting, I’m happy to accept donations too.


Unfortunately, it’s likely the site will stay somewhat quiet for a while still, and once it “stirs” back into life, it might not be the same site it was before. After all, I’m not the same person I was before. Maybe I won’t be as prolific about posting as before, but despite this, I hope that some readers will still enjoy my postings.

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Visited: SMPTE 2017 Exhibition Sydney (18 – 21 July)

After returning from my first long-solo-trip, I decided to spend two months “decompressing” and getting ready for my next trip. Part of the reason was so I could attend CeBIT, Vivid Sydney and SMPTE Exhibition. The last time I went was in 2015, and it was very much an event I enjoyed even though I’m not really in the production industry as such. As a technology enthusiast with a lot of interest in computing, radio, broadcast and satellites, it’s nice to keep abreast of new technology and developments that go into making the shows you watch and help deliver it from the studio right through to the end consumer.

On The Floor

This year, it was held in the ICC at Darling Harbour, much like CeBIT but it seemed the show-floor was more densely packed. Since the show is all about motion pictures/television engineers, they really know how to present their goods in a visually appealing way. It was mesmerizing in many ways – from walking past jimmy jibs swinging up and down running their demo, to rows of expensive Canon lenses, past racks of high-end digital microphone equipment, while looking at various analysis tools and bright LED panels. There was a lot happening, but I didn’t really have the time to “soak it in” as much as I would have liked, so I’ll probably recap on some of the highlights. I’d like to share some photos, but the terms of the SMPTE exhibition prohibit photography! Seems a little strange, but I might as well comply …

The first highlight was visiting Silicon Memory Technologies stand, representatives for a large range of brands related to computer storage including LaCie, Seagate, Akitio, Areca, Qsan, Stardom, Synology and Tiger Technology. At their stand, I was introduced to the Synology range of NAS products, as well as the Areca multi-bay DAS solutions. It was impressive to see an eight-bay Areca unit pushing about 1500MB/s read and 1000MB/s write over Thunderbolt (over USB-C connector). Even more interesting? They had a display case which had a Seagate Enterprise Storage 12Tb 3.5″ helium hard drive, as well as a Seagate Nytro XF1230 SATA SSD. Both products are pretty rare to see – I’d love to see even larger hard drives become more mainstream, so the existence of the 12Tb unit even if in limited quantities is encouraging to say the least. However, with the advent of the 50Tb 3.5″ SSD, it seems density is something hard drives might be losing out on, even though they are more financially economical in terms of purchase price.

The next biggest highlight was visiting the Blackmagic Design corner. One of the classic Aussie success stories, they have been featured even in documentaries such as State of Electronics and have been involved in bringing good value products to disrupt the market. It was interesting to see their real-time film scanner in action with 4k/30fps capability, as well as their newer (compact) scaler/format converters. Their product range is also diversifying into audio, so soon it seems they will have their feet in every part of the chain.

I took some time to drop into the Jands stand with the Shure Axient Digital system being on display. What caught my eye was actually the circular polarized antenna, as most in use are “paddle” shaped log-periodic dipoles. After the recent digital restack, the frequency bands available for wireless microphones had changed, so it’s probably something a lot of people might be interested in. It was interesting to hear their new digital system offers uncompressed audio, more channels, encryption and better range on an equal-power basis due to digital gain. It maintains interference mitigation capabilities, while also providing AES-3 and Dante digital connectivity. They also showed me a very tiny IP-rated manpack transmitter with integrated antenna and rechargeable battery – most impressive, as it’s even smaller than my wallet.

On that note, I stopped into the Sennheiser stand as well, just to see their offerings, and it seems they also have a digital offering of comparable feature-set, at least, on paper. But they didn’t take the time to explain it to me in detail.

Another highlight was visiting the Quantum stand – as it turns out, it’s the same brand as the formerly highly-regarded Quantum hard drives, just except they are providing storage solutions instead of drives now. Apparently they’re still heavily invested in tape storage, so that’s a good alternative for some niche applications.

I also stopped by G.Technology’s stand, represented by AVNET, since I spotted quite a few HGST products on show. Interestingly, I didn’t know HGST were into the SSD market as well, but they also have 4k-native hard drives on offer too. The Ultrastar He platform had offered 12Tb drives already, and I believe they had an SMR 14Tb drive as well, but again, are rarely seen.

As with the previous show, there were some drones on show – this year they focused on small compact drones, but CASA were also there raising awareness of safe operation and no-fly zones. They promoted an app at which details no-fly zones.

Rohde and Schwarz were also a nice stand to visit, with their analyzer and modulator being run in the front showing a nice and tight 256QAM constellation diagram. In the back, they were running their PRISMON system which was doing live PSNR and SSIM measurements with an HD-SDI input and a post-decoder output, allowing an operator to see the trend in picture quality over time as well as highlighting which parts of the image are most suffering from compression effects. I liked seeing that, since one of my bugbears is low-quality over-compressed video on the standard Freeview broadcasts – it’s part of the reason I like to keep an eye on their bitrates.

It was already a pretty good show as far as I was concerned. There were quite a few demonstrations from Sony, Panasonic and Canon as well, and various other equipment suppliers showing off several-hundred watt-hour battery packs. Of course, that was not all.

Getting Into Radio and Satellite

To my surprise, at the Sonifex stand, there was some Nautel transmitters on show. I had come across their products at one of the HFCC presentations in prior years at the Gold Coast. While I didn’t visit HFCC, because I was involved as a monitor of Radio Vaticana’s DRM broadcasts, I was aware of their program, so it was an honour to meet their representative and have a chat about where radio is headed. It was also exciting to see their “modern” transmitters in person – unlike older units where external test equipment and only basic displays are provided in the form of needles on gauges, these had touch-screen LCDs showing everything – spectrum, SWR, power, temperature, voltages, etc. It was also surprisingly compact and flexible too, but I suppose that’s what happens thanks to digital technology.

I stopped by Optus’ stand as well, where they were showing a 4k satellite demonstration program of soccer. It was quite nice and sharp, so I struck up a conversation about the service and whether it was “on the air”. He claimed it was on Optus C1, and running “about 20Mbit/s” with three trial services on a 36Mhz wide transponder. I said that was impressive, but pretty hard to fit that bit-rate in, to which he admitted that they were running a very low amount of FEC to make it happen. I also asked about Optus 10 and what it was “doing” – it is still at the old Optus B3 location but running commercial IP traffic. This corroborates what I had determined on my “hunt” for Optus 10 in 2015.

Lets just say, I couldn’t help myself but to go looking. The first step was to use my “existing” set-up that uses a TBS6925 Professional Satellite Tuner Card with my DiSEqC switch network, window cable (lossy!) and collection of Ku dishes. Unfortunately, as C1 is co-located with D3 and both are primarily used to push VAST and Foxtel paid-services, I only had a 76cm dish “shared” with another LNB to receive D1. As a result, this limited my SNR, resulting in this disappointing result.

They weren’t lying. It’s about 12607Mhz Vertical on C1, running DVB-S2/8PSK at 30MSPS with 9/10 FEC (!!). Very rarely will you see any commercial service use such little FEC, since it requires a very good signal to ensure continuous reception. It’s more common to see lower rates like 3/4 or 3/5, even down to 1/2 in rare cases being used. The final trick they used was to turn off QPSK pilots, which gives a tiny bit extra bit-rate, but also means that consumer gear with low-phase stability might have difficulty maintaining the lock.

Unfortunately, even though I had roughly 13dB SNR (after best alignment of the shared dish), I had a non-zero BER, so data errors were to be expected.

In spite of this, I managed to see that this carried the three test services as expected, with the first having about 27Mbit/s bitrate. Unfortunately, everything is encrypted with Irdeto, so nothing to watch for me.

Unsatisfied with this, I decided to use my other computer that has a Prof Revolution 8000 tuner – this is a cheaper tuner without ACM/VCM or APSK abilities, but is enough for this particular signal. Since it was nearer to my dishes, and I had a “spare” 75cm Ku band dish on a caravan stand, I crimped a fresh RG6 Quad-Shield lead for the Sharp Dual 10700Mhz wide-band LNB to maximise my chances. After all, the above result was from a Sharp Quad LNB, and those normally have a higher noise-figure. With the dedicated dish and a short cable run resulting in a “high” signal, the SNR appeared to be the same (since this other card under-reports) but the signal was error-free.

In my experience, cheap Chinese made 75cm dishes rarely get more than 15.2dB on “on-air” signals, and the best I’ve seen from my 85cm dish was about 17.2dB, so this was about what I would expect.

At that point, the bitrate was more about 28.6Mbit/s on the first Test Service. The NIT clearly identifies the service as belonging to Optus.

Interestingly, the provider name for the first service is set as Harmonic – a provider of encoders and one they had used in the past as well.

Based on the mux area usage, Service A is mostly constant, with B varying slightly over time. There’s still about 11% of the multiplex left in null packets, so it’s not the tightest fit. Still quite admirable, but what a shame I didn’t get any footage from it.

Before leaving, I decided to stop by Telstra Broadcast Services’ stand as well, just to have a chat. It was there that I realized that some of that I was seeing on the air (namely on D2 and Intelsat 19 having some carriers change names to Telstra Broadcast Service) was a result of their acquisition of Globecast Australia. That explains a lot, but I’ve always had good experiences tuning in to Globecast Australia feeds, and we still see some encoders set-up with the old names even today. Even in the new year, I can thank Telstra for bringing us the Sydney Fireworks. It was good to hear from them that the Satellite market is still in high demand – unlike the domestic DTH market where we’ve seen a few providers sink under the water in a few years (e.g. UBI World, SelecTV) and FTA is starting to become rare.


I’m glad I had the opportunity to visit SMPTE Exhibition this year, given that I’m flying out of the country next week. It’s always good to get a refresher on what is “leading edge” technology, even if it is in an area I’m not professionally involved in at this moment. I’ve always had an interest in the technology, and I’ve always been involved “at the fringes” as a technically minded consumer, so seeing it up-close and having the opportunity to discuss it with people who are in the area on a daily basis is both insightful and valuable to me.

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Review: Sandisk Ultra UHS-I 128Gb microSDXC Card (Up to 80MB/s)

At the beginning of this year, I posted about a relatively new (less than a year old) Sandisk Ultra UHS-I/Class 10 microSDXC card of the 80MB/s variety which had a data loss issue. Rather unfortunately for me, I had some personal data at the time, and my doubts got the better of me so I gave it a “second chance” since a full format and immediate integrity test passed.

Half a year later, the same demons returned. The phone it was used with started to freeze in strange ways. It was spending forever just to load up the lock screen. Eventually, I could have no more, so I removed the card and the phone went back to normal. Plugging it into the PC revealed exactly what I had come to expect of the card – data loss.

The Bad Egg

Unfortunately, the bad card was not actually reviewed on the site. When I purchased it, I was in such a hurry to commission it for use that I did the testing, neglected to save the results and never said anything about it. The bad card looked exactly like the old (pre-80MB/s edition) 128Gb cards from the front and back, with a green rear substrate with a black “painted” portion with codes. The difference was that it was a superior card when it came to read speeds as compared with the older one.

Unfortunately, it was also superior in losing data. While its older sibling still recalls data flawlessly, this one has failed twice in succession.

Its behaviour in my two preferred card readers proved to be interesting – the RDF8 seems to “time out” waiting for the card, drops the bus and says goodbye. The more patient RDF9 seems to accurately delineate which sectors could not be read and is a better candidate for doing data recovery on “slow” cards. Good to know in case there are other cards that might need recovery.

Regardless, there shouldn’t be any read errors especially for a card which hasn’t been mistreated (e.g. removed during writes), especially when the errors seem to coincide with files that had formerly been readable. I decided that it was time to return it.

The Replacement Egg microSDXC Card

Armed with all the necessary documentary evidence, I set out to return the card. I tried to call Sandisk and obtain an RMA number over the phone as the receipt had encouraged me to do so, but instead, I got a “You are not allowed to call this number,” message and then it hung up on me. As a result, I had no option but to return to the shop without an RMA number, faded receipt in hand.

Contrary to my expectations, the RMA process with Wireless1 was very easy and painless. Once they had identified the receipt number from the faded receipt, I provided the documentary evidence and they were able to issue me a new card on the spot, along with a replacement receipt on regular paper which shouldn’t fade. Much more painless than I had expected.

The package looks just like the original problematic card, and differs from the original version with the increased “Up to 80MB/s” claim.

The internal package, however, is somewhat different. The troublesome card came in a plastic pack but with a paper backing that had been adhered to the plastic. This one uses a cellophane cover over the back instead.

When it comes to “ease of use”, this new packaging was not particularly user-friendly. Despite following their open instruction, the cellophane shredded mid-tear, so I had to use some extra force to break it free.

The card itself looks different. The green substrate is gone, instead replaced by a uniform black at the back. I have good hopes this card may be different – maybe it will perform better and not lose my data?

Card-specific information is as follows:

Capacity 127,865,454,592 bytes
CID: 03534441434c434680e3572a1d0112df
CSD: 400e00325b590003b8ab7f800a404079

Of note is that the card capacity is different to the original cards – another hint as to a different implementation.

Performance Testing

Before using any card, it has to pass a commissioning test to ensure its correct operation. It makes an ideal chance to characterize its performance as well. In this review, the card will be tested with both Transcend RDF8 and RDF9 readers.

HDTune Pro Sequential Read

The card achieved an average of 79.7MB/s with the Transcend RDF8, just shy of the claimed 80MB/s. However, it did achieve an average of 89.7MB/s with the Transcend RDF9, exceeding the claims.

HDTune Pro Sequential Write

When it comes to writes, the card seems to have some bumps in the speed, but averaged 26MB/s on the RDF8 and 26.2MB/s with the RDF9. This exceeds the Class 10 minimum requirement of 10MB/s, and compares quite favourably with the Samsung Evo+ which achieved around 20-22MB/s. Based on sequential performance alone, this card is more than a match for Samsung’s Evo+.


Testing with CrystalDiskMark has been something I have been doing for a long time, but this card seemed to present some interesting challenges.

Transcend RDF8

When running the tests multiple times, some rather interesting deviations in the 4k performance seemed to present itself. While very slow rates are not unexpected, only on one test was 2MB/s achieved. In the last run, it hung for hours preparing the QD32 tests, and never finished.

Transcend RDF9

The test was run once on the RDF9, and the results look quite good, although the 512kB read accesses are slower than that of the RDF8 by almost half.

Because of the inconsistent performance, the results from this benchmark will not be included in the performance test database. It does point to a bigger issue, which will be subsequently discussed.


Because CDM often has some strange results when it comes to 4kB accesses, I’ve gone back to using ATTO. However, even it was not fraught with trouble.

Transcend RDF8

When running ATTO initially, the card produced errors. The program claimed to have errors on reading the file, which seemed suspicious. On dismissing the dialog, the card was found to have an unacceptably slow write speed at 1kB accesses.

Thinking that the card may be a bit stressed under threaded-access, I disabled it and managed to obtain a result.

As the result was taken under a different test regime, it’s not possible to compare it with other tests. However, strangely, it seems that the card had very poor write throughput under 64kB, where it magically recovered.

Further testing showed it was possible to do overlapped I/O tests, but only after giving the card some time to rest. This suggests the card’s controller is perhaps acting similarly to some older SSDs which may have lacked processing power to manage the flash mapping table and perform garbage collection in the background when subject to heavy I/O and instead, resulting in “stalls”. If not that, it could be possible that the card has a throttling mechanism to attempt to prolong its life when used in inappropriate situations that involve numerous small-writes. This inconsistent I/O behaviour makes understanding its small block performance difficult.

Transcend RDF9

Repeating the same test with the other card reader still resulted in inconsistent behaviour, and results that seem to defy expectations – notice how some writes reach 50MB/s. This may indicate that the “peak” performance is higher than seen in the sequential test, but this performance cannot be maintained over the long run.


Under more normal read/write situations with the RDF8, no data errors occurred and throughput was close to expectations.

Discussion – microSD Endurance, IOPS, TLC and Beyond

This card is the first card to really frustrate my attempts at benchmarking it. The I/O behaviour of the card seems to vary as a result of the previous access patterns and amount of “dwell time” between tests. The speed does also vary from reader to reader subtly. The reason for this isn’t entirely clear, but as I had earlier stated, my hypothesis is that the card’s internal flash mapping table management and CPU may be responsible for a bottleneck when many small accesses occur in quick succession. This maybe because the card is attempting to consolidate writes (maybe it has some pSLC cache?) or do some garbage collection/wear levelling. An alternative hypothesis is that this is an attempt at write-throttling to attempt to prolong the card’s lifetime in some “abusive” applications which result in constant writes.

For normal uses which involve bulk data transfers in large blocks, the card seems to perform just fine – in fact, for a “value segment” card, its performance is notably good. However, if small accesses are necessary, this card’s inconsistency does make it a little hard to recommend. Use in single-board computers to run operating systems is one place I can envisage such I/O limitations to cause problems.

Unfortunately, where high density consumer flash storage is involved, it is very likely all products are now triple-level cell (TLC) flash with a more limited endurance of somewhere between 300-500 cycles (realistically speaking). As a result, if you carefully read the warranty guidelines, Sandisk excludes warranty for:

(i) normal wear and tear, (ii) video monitoring, security, and surveillance devices, (iii) internet protocol/network cameras, (iv) in-car recording devices/dashboard cameras/black box cameras, (v) display devices that loop video, (vi) continuous recording set top box devices, (vii) continuous data logging devices like servers, or (viii) other excessive uses that exceed normal use in accordance with published instructions.

Other manufacturers are following suit as well. As a result, if you do operate such equipment, using “regular” microSD cards may result in rapid failures which can be disastrous – imagine a security camera or a dashcam that had destroyed the card, but the owner is not aware until they try to recover the footage post-accident. The card that failed before was not subject to any abusive use, but still began to lose data.

As a result, Sandisk has introduced a high endurance product category as an answer to their needs, however, they’re not so clear as to how much endurance they have, merely to claim up to 10,000 hours of Full HD recording for the 64Gb card, and 5,000 hours for the 32Gb card. Of course, the amount of writes depends on the bitrate – their specification is based on 26Mbit/s, so from my math that’s:

5000h * 3600s * 26Mbit/s / 8 = 58,500,000MB written
32Gb card = 32,000,000,000 bytes
          = 32,000MB
Cycles = 58,500,000/32,000
       = 1828.125

The endurance is a lot higher than your “average” TLC 300-500 cycles, but still falls short of MLC’s (approximately) 3000-5000 cycles. Maybe it’s MLC and they’re being a bit conservative, but it’s still interesting to know. Unfortunately, the price you pay is the cards only claim up to 20MB/s read and write speeds.

The issue of uneven I/O performance also seems to be something the industry is trying to work around, with the introduction of “A-class” figures (Application Performance Class) which is supposed to denote the IOPS performance capabilities of cards. However, this hasn’t really been seen on consumer level products at this stage.

But before things get better, it seems we might be on track to make things worse. Increasing demand for flash, a supply shortage and the constant demand for lower price has moved the market to contemplate and manufacture quadruple-level cell (QLC) flash which pushes the boundaries even more, with potentially worse effects on write speeds, data retention and cycle endurance. At this stage, it’s pretty hard to be enthusiastic when the shortcomings of some TLC products are already rearing their head.


I managed to get my card replaced painlessly on the spot at Wireless1, which was great, and the replacement card is of a different design to the original. Sequential speeds were quite good, achieving about 80MB/s-90MB/s on read and about 26MB/s on write which makes it the best 128Gb microSDXC card I’ve tested so far.

However, the random small block performance proved to be problematic to determine as the card appears to stall when subject to large numbers of small accesses, requiring time to recover. As a result, this card is not recommended for applications where small accesses may be necessary – e.g. use in single-board computers as primary storage. Why this card stalls is not known for sure, but could be related to its internal organization or a deliberate attempt to preserve its life through write-throttling. It is the first card to frustrate my benchmarking attempts, and for that reason alone, deserved its own blog post.

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