VMware Cloud Community
Confusioner
Contributor
Contributor

Low disk performance on Dell T7400 with Perc H700

Hi,

I'm pulling my hair trying to figure out where the problem is. Here is the setup:

- Dell T7400 Workstation (Intel 5400 Chipset)

- 2 physical x Intel Xeon X5482 @ 3.2Ghz

- 64GB DDR2-5300F 667mhz ram (8x8GB)

- [Disabled] Onboard Perc 6/i (LSI 1068e SAS/SATA 3.0Gb)

- DellPerc H700 Integrated, 6.0 Gb/s, 512MB, Has functional Battery, Forced Write back enabled, FW 12.10.3 (plugged to 16x PCIe 2.0) - Salvaged from a Dell T710 Server

- [Raid-0 on H700] 2 x Seagate Constellation ES 1 TB 7200 RPM SAS 2.0 6 GB/s (ST31000424SS) - Stripe size: 64KB

- 1 x Crucial M550 240GB SSD connected to onboard Sata AHCI @ 3.0Gb/s

The problem: If boot to a disk that has Win7x64 on it, I get disk speeds around 270MB/s from SAS Raid-0 to SSD or other way around. If I boot to ESXi 6.0/5.5/5.0 on the same machine without changing anything, I get disk speeds 100-110MB/s inside the VMs (ALL Thick disks, eager zeroed, Win2008R2 and Win2012R2). Copying between the datastores seems to have same speeds. I have tried various LSI drivers, flashed the H700 multiple times, Installed ESXi to different disks but nothing substantially changed. I played with Disk Share value on the VMs and increased to 4000 max, which resulted in extra 15MB/s increase in speed. I read numerous articles regarding disk queue depth, disk latency but the fact that Win7x64 gets the proper speeds pointing to non-hardware issue. Any help will be highly appreciated.

Tags (2)
Reply
0 Kudos
0 Replies