I'm looking at replacing an old file server sharing a single RAID5 volume powered by 6 10K rpm disks with 8MB caches. The replacement will be 2 RAID10 volumes of 4 disks each. The new disks have 64MB caches... but are only 7200 RPM SATA drives (WD RE4). My question, then, is how would you expect the two volumes to perform comparatively?
This is already a done deal, but I ask the question because I'd like to have an idea of what to expect before I deploy this. My gut tells me the new system should be a nice performance upgrade, especially because of the split to two volumes instead of one. I'm also curious how it would compare if I only had one new volume instead of two.
I worry I may be under-estimating the impact of the rotation speed of the old array. I also worry because, while I expect the new system to be faster, it's also much larger, and therefore will eventually see an increase in the absolute amount of data transferred per unit of time... so is it likely to be enough faster to handle this increase?
Since I know it does matter, this is for a traditional file server that will be used for mapped drives. No database, web servers, or anything like that.
If I get the chance, I'll run some actual benchmarks to compare the new and old arrays with real-world usage and post them after deployment, but again, the true test won't be until the new system is handling as much data transfer relative to it's size as the current system.