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By Solandri on 9/8/2010 1:07:36 PM , Rating: 2
USB 2.0 is about 20-25 MB/sec in RL benchmarks. A 20 GB file copy that's USB-limited should only take about 15 minutes.

The slowness you're encountering is due to the speed of the flash memory in your USB stick. Solid state memory is still a lot slower than hard drives. The high speed SSD drives being put into new laptops get around the problem by having multiple controllers writing different parts of the file to multiple portions of flash memory simultaneously. Like a huge RAID-0 array of 4, 8, 12, or 16 drives. Unfortunately, most USB stick drives only have one controller so suffer from the full slowness of flash.

Also, adding a RAM cache will not help with a large transfer like a 20 GB file copy. It only helps when there's a cache hit due to some commonality in the files. I suspect the "40 MP3 files" they're talking about in the article are the same MP3 file being read over and over 40 times. Except for databases, real-world usage patterns rarely have that high a cache hit rate.

By ekv on 9/8/2010 2:09:20 PM , Rating: 2
I was kind of thinking the ram cache would act as a cache AND a write buffer. But that would only help if the controller could write to more than one flash chip at a time. I don't think the Express Drive series does that.

Why? you might ask. Super Talent also has a USB 3.0 RAIDdrive series that does emulate a RAID 0 setup. This is an older article but it suggests a serious performance improvement,705134/Super-Ta...

If you want performance, RAIDdrive is the way to go, though I could only find it for $219 (32 GB). Ouch.

