Strange problem

By Crisse | January 1st, 2009 | 9:48 am

I have Acer Aspire One A150 with Windows XP, computer itself has two memory card readers.

I have two SanDisk Extreme III SDHC cards (speed 20 MB/s 133x). Other is 8 GB and is 4 GB, both with same speed.

I used my 4 GB card with latest eBoostr and speed test showed that  the randow read speed is 18406 kb/s. That sounds perfect. I plugged my 8 GB card in and answered yes when the program wanted to create a cache file to that card. After speed test it showed that random read speed was about 14000 kb/s although larger memory card has exactly the same speed specs than 4 GB card. What can cause this difference? Is there some “size limit” or is eBoostr just unable to use larger memory cards fast enough?

After I reformatted 8 GB memory card and allocated only 5244 KB for eBoostr I got almost the same random read speed with both cards (a little more than 18000 kb/s). It seems that memory card is working properly.

Do you have any idea what could cause that random read speed drop with larger space?

New Year wishes

Christian S. from Finland

2 Responses to “Strange problem”

  1. devsk
    Jan 01, 2009

    I talk about this issue in my post as well. The thing is eboostr is creating a huge file in the native FS to store its internal cache. So, 8GB file on a 8GB drive is bound to fragment badly in the native FS. I know people say random access time is low and fragmentation is not an issue with flash. But think about it: if you have 20 fragments in the native filesystems, a cache read/write may result in 20 random read/writes in the worst case. Transfer speeds are bound to fall.

    eboostr should either create a folder and use the native FS for storing cached files Or it should format the drive in its internal format (whatever it is using to organize files within that huge 8GB file) and use it directly if I choose all of the drive for cache.


  2. Crisse
    Jan 01, 2009

    Ok. That sounds logical, thanks DEVSK!

    Does anyone know what is the largest reserved size from memory card for eBoostr to get the fastest possible speed?

    Unfortunately eBoostr is unable to handle a single memory card as several drives (as far as I know). That way fragmentation could stay lower and speed faster.

    Best regards
    Christian S.



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