Hi,
I recently built a desktop PC and my hard drive I/O performance is abysmal.
I’ve built numerous systems over the years, but this is the first system where I’ve used the RAID support built into the chipset.
The motherboard is an Asus P8Z77-V PRO. I’m using an Ivybridge i7-3770K processor and have 8GB of RAM. This motherboard uses the Intel Z77 chipset which includes Intel Rapid Storage Technology (IRST).
I have five 2TB Western Digital hard drives. Three are WD20EARS and two are WD20EADS. The SMART status of all drives is “healthy”.
I used the Intel RAID BIOS to configure a RAID5 array using all five drives to create a 7.3TB volume. I used UEFI to boot/install Windows 7. The system works very well except for the disk I/O performance.
I’m using HD Tune to measure disk performance. I routinely see transfer rates close to 500 MB/sec when the system has been idle. However, after sustained disk activity (20 to 30 seconds) the read and write performance drop to below 10 MB/sec. It’s abysmal. My apps hang while they wait for their disk operations to complete.
I’m running Windows Media Center and if I’m recording two HD programs, I can’t do much else on the system. This is not right. My previous Lynnfield system (without RAID) could easily record two programs and run plenty of other applications simultaneously without a problem.
I believe there is something wrong with the Intel RAID5 implementation. Can you corroborate this?
Do you know of any configuration changes I can make within Windows 7 that can mitigate this problem and improve disk performance?
Thanks,
John