Unsolved
7 Posts
0
894
PERC 730p + SAS RAID10 + SAS SSD?
I have a Poweredge T640. I'd like to run a 6xSAS 12Gb/s RAID10. OK, simple enough. Now is where my confusion comes in. I know you can use SSD Caching with SATA3 HDD's and SSD's and that will significantly impove RAID performance, but...
Will a SAS 12Gb/s SSD beat the caching from the PERC 730p onboard? That may seem like a silly question since its 12Gb/s vs 6Gb/s but it's tough to find info regarding this topic. Does SAS SSD caching cause a significant performance increase? Basically, is it worth it?
I've also seen recommendations to run the SSD cache with 2xSSD's in RAID1 instead of a single drive in event of an SSD failure but that shouldn't cause any performance issues.
sLaNj
7 Posts
0
May 28th, 2019 10:00
I should clarify. I'm using 12Gbps SAS HDD's in RAID10 and want to use a different 12Gbps SAS SDD's as cache. All 512GB of it. The 2GB on the controller can beat that even as flash?
DELL-Daniel My
Moderator
Moderator
•
6.2K Posts
0
May 28th, 2019 10:00
Hello
If you are asking about setting up a 12Gb SSD as read/write cache with a set of 6Gb SSDs in RAID 10 then I would not expect much of a noticeable performance increase.
No, the cache on the controller is memory, it is faster than any SSD.
Thanks
sLaNj
7 Posts
0
May 28th, 2019 11:00
This client will be reading from the data far more than writing to it. The data is stored on the server once and accessed 50+ times at minimum. So in this instance you'd say the SSD's would be useful for read cache? If so, what's the reasoning? Boss is gonna ask me why is better. :)
DELL-Daniel My
Moderator
Moderator
•
6.2K Posts
0
May 28th, 2019 11:00
Yes, the controller cache will be faster than the 12Gb SAS SSD. The controller cache is only write cache, not read. The only time an SSD write cache drive would be useful is if there are sustained writes that would cause the controller write cache to fill up waiting on the SAS HDDs. The controller would be able to offload from cache to the SAS SSD faster than the SAS HDDs.
I think the controller would be sufficient as write cache with 12Gb SAS HDDs in RAID 10. You may want to use the SSD as read cache.