Performance Issue: SDXC card vs. IEEE-Harddrive

[TomDTL]

Hi,

I have Macbook. I am using Virtualbox for running Windows XP and Windows 8. Originally I started off saving the virtual harddrives on my internal SSD, but after a while they just consumed to much space on my HD. Thus I moved them to an external harddrive that is via firewire connected to my Apple device. Still everything worked fine and the performance was okay.

Later I had the need to think of more mobile solution. I thought placing my virtual harddrives on an SD card might be a very mobile idea. So I headed for PhotoFast Memory Expansion Combo Kit. That is actually just a tiny adapter for micro sd cards that fits perfect in the sdxd slot of my Mac.

Anyhow, I moved the virtual disks to a SanDisk 64 gb SDXC Class10 u1 AND since then they perform ugly slow! Why? Do you have any hints regarding that performance issue?

What I have tried:
- Reformating the SD card (exFAT, HFS+)
- Tick "SSD" in the properties of virtual box
- using a different SDXC adapter in the USB slot

Nothing helped ;-(

Thanks in advance.

Ciao tom

[BillG]

That is pretty much what I would expect. SD cards are not SSDs! Read/write speeds for SD are about 12Mb/sec. SSD speeds are up near 1Gb/sec.

[TomDTL]

Hi,

damn I am really disappointed. I checked the read and write speed:
- SSD > write about 250 MB/s read about 500 MB/s
- HDD (on IEEE) > write/read about 65 MB/s
- SDXC via USB > write 6 MB/s read 16 MB/s
- SDXC via internal reader > write 12 MB/s read 45 MB/s

Now I got the picture. Might there be any possibility to speed my slow SDXC cards? Obviously not ;-(

Thanks for your hints.

Ciao tom