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RAID 0 performance inquiry on an 840 EVO (250GB)

Last response: in Storage
March 25, 2014 7:54:08 AM

I already own one 840 EVO and was wondering its performance on a RAID 0 regarding its turbowrite cache. Do the two drives combine their cache and then once it runs out of cache to write data to, then does it get that drop in performance?

If it just uses the cache of one drive then I might as well just get an 840 pro or upgrade to a bigger EVO.

Also, yes I'm aware RAPID only speeds up the performance of one drive in RAID 0. Just really wondering overall what experiences people who own an EVO in RAID 0 have noticed.

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a c 179 G Storage
March 25, 2014 8:07:47 AM

If you use two ssd's in raid-0 using motherboard raid, they will each act independently.

Raid-0 has been over hyped as a performance enhancer.
Sequential benchmarks do look wonderful, but the real world does not seem to deliver the indicated performance benefits for most
desktop users. The reason is, that sequential benchmarks are coded for maximum overlapped I/O rates.
It depends on reading a stripe of data simultaneously from each raid-0 member, and that is rarely what we do.
The OS does mostly small random reads and writes, so raid-0 is of little use there.
There are some apps that will benefit. They are characterized by reading large files in a sequential overlapped manner.

I have done this before, with different ssd's and found no real world benefit.
The only benefit of raiding two ssd's for me was to get a larger single image of the "C" drive.
I replaced them with a single larger ssd and was very pleased.
In the end, a single larger SSD seemed to be faster.

If you have some available system ram, you might want to read about and activate the Samsung magician cache.
March 25, 2014 8:17:53 AM

Thanks for the detailed answer :)  I guess once NAND becomes even more cheaper I'll purchase a bigger SSD. Still very weary about the TLC in the EVO but so far I don't see any reliability issues and buying a 512GB pro is cheaper than buying two 250GB EVO's anyway.
a c 906 G Storage
March 25, 2014 4:38:24 PM

BTW - you lose Rapid when in raid mode