Slow Write speeds Sandisk Exteme 120GBx2 in Raid 0

Is it normal for write speeds to slow down a lot? Read has slowed a little but not too horribly. After my raid setup and Windows 7 x64 install I did a bench and got 670 read and 640 write or something like that. ( both were mid 600’s ) Now I am getting this:

Seq Reads 552

Seq Writes 105.6

4k Reads 30.57

4k writes 1.464

TRIM is not supported in RAID. If you have done a lot of benchmarking or write activity the write speed will slow down. You will either need to get a manual TRIM tool or create an image of your OS and secure erase the drives then reload the image. TRIM is currently not supported by any SSD I have heard of in a RAID environment. 

Yeah, I knew Trim wasnt supported, was hoping the garbage collection would be enough to keep it cleaned up. Just wasnt sure why the writes took such a huge hit and not read speeds or if that was even normal. Thanks for the quick response :slight_smile:

That is normal. Writes to a cell that has previously been written to requires a read, erase then write. This is what cases the performance degradation. Reads only require read so they will not really suffer from this issue.