Lexar Rev. A versus Rev. B

[stevefal]

Searching the forum I only found one mention of a Lexar CF revision number. I have four 64GB cards, and was benchmarking them with Blackmagic Disk Speed Test. I noticed that one seemed slower. Checking the labels, sure enough that one shows Rev A, Copyright 2011, and the other three are Rev B, Copyright 2012.

Unfortunately, the benchmarking tool yields varying results. Just as we've noticed with ML, disk speeds can increase after the card "warms up". But I have also noticed with the BMDST that they can also slow down during a long run.

In either case, it seems like the Rev B cards average about 10-15MB/s faster than the Rev A. Especially noticeable is how the Rev B cards achieve their top speed pretty quickly, whereas the Rev A seems to take some time. I only have one Rev A to test.

Anyone else have two (or more) revisions? Able to measure a difference?

[EDIT] I've benchmarked again and can't repro the difference reliably. In one case a Rev B card came up fast and then dropped to 75MB/s for a while. I suppose I should try the ML tool or some other long-run benchmark.

[RenatoPhoto]

you may want to review some of the settings used during benchmark:


Benchmark was developed to measure maximum speed performance at different cluster size.

I believe during playback-benchmarking there is less use of the CPU so that the highest recording speed can be obtained and compared to what the manufacturer claims.  If you benchmark in movie mode then there are a lot of settings that can slow down recording so it is not recommended to test in this mode.

To Benchmark you card properly for MAX speed compatible with ML:

1. Go to ML and turn OFF Global Draw
2. Do not test while LV is active, meaning not in video mode or photo with Live View Mode.  This is refereed to testing in Playback mode
3. Make sure your Camera Auto Power off is disabled in Canon menu.
4. Go to the ML menu and find the Debug menu and then the Benchmark, and select Card R/W benchmark (5min)

When the benchmark has finished ML will automatically record the bitmap image in your card.


VERY IMPORTANT

Make sure that in Canon Menu:
Image Quality = Raw for (5D3, 650D,  ....) some others may be better in jpg
Auto Lighting Optimizer = OFF
Long exp. noise reduction = OFF
High ISO speed NR = OFF
Highlight tone priority = OFF
Multiple Exposure = Disable
HDR Mode = Disable HDR