HP DL320e G8 v2 + P222 + 2xSamsung SSD 850 PRO 2TB - Physical Drive Write Cache vs. Controller Cache

[kaspet]

Hello,

I have following configuration:

- HP DL320e G8 v2 (Windows Server 2012 R2)

- Smart array P222 (512 MB with backup battery)

- 2 x Samsung SSD 850 PRO (2TB with 2GB LPDDR3 RAM) - RAID1 configuration

- Smart Array Controller Physical Drive Write Cache is Disabled

- Smart Array Controller Cache is Enabled (25% Read and 75% Write)

- HP SSD Smart Part is Disabled

I have an issue that performance of SSD drives is extremly slow at writes on disk.

If I enable also Physical Drive Write Cache the performance is significally improved, since 2GB of Drive Cache is used.

On second server I have following configuration (just for testing):

- HP DL320e G8 v2 (Windows Server 2012 R2)

- Smart array P222 (512 MB with backup battery)

- 1 x Samsung SSD 850 EVO (1TB with 1GB LPDDR2 RAM) - no RAID

- Smart Array Controller Physical Drive Write Cache is Disabled

- Smart Array Controller Cache is Enabled (25% Read and 75% Write)

- HP SSD Smart Part is Disabled

In this second configuration write performance of the SDD disk is almost as by Samsung SDD specification.

If HP SSD Smart Part is Enabled my both server configurations preform on Write really bad and therefor I disbled it (also recomended by some posts on this forum).

What could be the reason of bad write performance in my first case (2 x SSD in RAID1)?

If I do setting as Physical Drive Write Cache is Disabled and assign 100% Controller Cache for Write, will be Disk Cache (2GB LPDDR3 RAM) used for Read and Controller Cache for Write ?

If Physical Drive Write Cache is Disabled, is all Disk Cache used for Read operations ?

Could be the problem of Controller Cache size in RAID1 configuration, since without RAID is performing OK ?

Thanks for all helpfull posts.

[Patricck]

Hi,

have you managed to solve the issue?

I am also planning to get a P222 with SSD850 PRO in RAID1.

Thanks