PixelFlash ad. is inaccurate

[Happy Hopping]

http://www.ebay.com/itm/USB-3-0-Com...ory_Card_Readers_Adapters&hash=item27cb95a43a


Approximate transfer speed of the ™ USB 3.0 CF Card Reader

SD Movie (6 GB) / USB 3.0 / 20 sec.

I bought PixelFlash USB 3.0 CF Card Reader, according to their ebay ad., I should be able to do 6 GB at 20 sec.

Tonight, I have only 555MB in my 2 GB CF card, it took about 18.36 sec. to transfer to my RAM drive.

So is this Pixel Flash CF Card even USB 3.0? The CF Card itself is Sandisk Extreme 4, and my PC is 2 x Xeon 6 core at 2.8GHz

 

[evilsofa]

555MB in 18.36 seconds is 30MB/sec, which is right in the middle of their estimates of read performance on a legacy 2.0 system.

So, what motherboard do you have? Does it have USB 3.0, or are you using a USB 3.0 expansion card? Do you have USB 3.0 drivers installed?

 

[diizzy]

http://www.hjreggel.net/cardspeed/
Looks reasonable
//Danne

 

[Happy Hopping]

555MB in 18.36 seconds is 30MB/sec, which is right in the middle of their estimates of read performance on a legacy 2.0 system.

So, what motherboard do you have? Does it have USB 3.0, or are you using a USB 3.0 expansion card? Do you have USB 3.0 drivers installed?

I use HP motherboard, it's a Z800 professional workstation. It does not have USB 3.0, so I have to use a expansion card. w/ their PixelFlash Card read driver, is a bit slower, at 18.55 sec. The expansion card itself does have its USB 3.0 driver that I installed

 

[Happy Hopping]

http://www.hjreggel.net/cardspeed/
Looks reasonable
//Danne

that link only have USB 2.0

 

[Billy_nnn]

The reader won't make the CF card itself any faster - if the CF card can only do 30MB/s then that's all you'll get, no matter what reader you put it in!

The ad is a bit misleading though - they claim 6GB in 20secs, which is about 300MB/sec - while their CF reader may be theoretically capable of those speeds, AFAIK there isn't a CF card available which is anywhere near that fast - I think the very fastest can read at up to about 150MB/sec (write speed is generally much slower), however they are very expensive, relatively speaking!

 

[evilsofa]

Looks like PixelFlash is indeed more than a little misleading in their advertising:

http://forum.thinkpads.com/viewtopic.php?f=58&t=104079

Not much in the way of reviews for this product, apparently because CF readers are a niche market in decline. I found a few remarks from people using it on USB 2.0 systems that thought it was great, but they had not tested it on USB 3.0.

 

[PixelFlash]

Hello [H]|[F]ers,

Thanks for taking the time to discuss our product.

To clear up any confusion, our USB-3 SuperSpeed CF Reader will indeed accommodate a throughput of bit rates up to 500 MB/s. As mentioned above, this is well beyond the speeds available with current CompactFlash technology (the max being about 150 MB/s at the time of this writing). So why build readers that can allow 500 MB/s throughput? The USB 3.0 protocol allows it and it gives our memory readers a significantly longer shelf life, speedwise. Future-proof is a quality that we think most of our customers sincerely appreciate.

Billy_nnn hit the nail on the head in that a CF Card is only “potentially” as fast as the speed rating associated with the card. For example, a 10 MB/s CF Card, will not transfer data at 500 MB/s by using a USB-3 card reader.

You may see some cards perform slightly faster than their speed rating, but this is the exception. For example, here is a video of our CF Reader being benchmarked via ATTO, with a 600x (90 MB/s) card. We also have seen slower than advertised test results with older CF cards of all brands, that have been in use for years.

diizzy’s link is also helpful as it shows the Sandisk Extreme IV 4GB card reaching 36.27 MB/s read speed (using h2benchw) on a firewire 800 connection. In any event, utilizing h2benchw or ATTO with identical settings in your own test will provide a more accurate comparative analysis and help identify if there is any sort of bottleneck in your testing procedure. One thing we guarantee is that our CF reader will never be the source of your bottleneck.

On occasion our customers have needed help and we’ve assisted them in identifying speed obstructions in their systems. If you have an issue, our support team can help, feel free to reach out to us. Thanks again guys.

 

[diizzy]

http://www.hjreggel.net/cardspeed/speed-by-cards-cfu.html#cdet-scx4
...for those who cant find it, both FW800 and PCIe interface readers are used.

While I do understand that Happy Hopping finds the specs misleading my personal experience is that rated speeds can be a bit misleading compared to real world performance. My SanDisk Extreme USB 3.0 Flash Drive says "up to 190Mbyte/s read speed" and I've never seen that but around 140-150 which is in my opinion "close enough" as you have a myriad of parameters that may differ compared to their tests such as raw read (I would expect thats the main cause), cluster size, file system, USB controller etc. Not saying that I find this kind of marketing ok per say but it usually works this way...
//Danne