Windows 7 Software Raid 0 Performance

MiikeB

Does anyone know how large of a performance increase I can expect with software raid 0 in Windows 7? How much memory will it take up?

I currently have a Lenovo w520 configured with a 160GB SSD and a 750GB HDD in the DVD spot.

I am of moving to dual 750GB/1TB HDD and adding a 256GB MSata Drive. The two HDD in Raid 0 would be for running a VM lab, some Linux VMs to learn on etc. I think if the performance boost is nice from RAID 0 would be nice if I plan on running 6-7 VMs (Laptop has Quad i7 and 16GB Ram). Would I be better off with something like Flexraid (I don't know much about it)? Or maybe having a VM running freenas that gets run from the MSata drive and uses RDM (does VMWare Server support RDM?)

I would be backing up to an external of course.

Also just out of curiosity does anyone know if I have a USB 3.0 drive can I use RDM to present it to a VM running in VMWare Server?

WafflesAndRootbeer

That product doesn't utilize mSATA. The best you can do on that product is two SSDs in RAID and a third HDD/SSD in an optical bay caddy. Bump the RAM to 32GB and you'll have a monster machine for all your uses, especially if you go all SSD, which you should if you can afford to.

ptilsen

Using HDDs, performance increase for software RAID 0 is almost double for reads and writes. Resource overhead is minimal. Using SSDs in RAID 0, gains will be mixed. Killing TRIM support means long-term, RAID 0 will effectively do little for write speeds. Personally, I wouldn't do it with SSDs. I might do RAID 10, but frankly the speed and reliability of a good SSD is enough that it isn't necessary. I wouldn't do RAID 0 on HDDs either. The chance of failure is so high for such a low gain compared to what an SSD will bring you. You might get comparable sustained reads and writes on RAID 0 HDDs, but access time going from milleseconds to nanoseconds ultimately means SSDs are much faster for most tasks. For VMs in particular, an SSD will definitely outperform 7,200 RPM HDDs in RAID 0.

MiikeB

ptilsen wrote: »

Using HDDs, performance increase for software RAID 0 is almost double for reads and writes. Resource overhead is minimal. Using SSDs in RAID 0, gains will be mixed. Killing TRIM support means long-term, RAID 0 will effectively do little for write speeds. Personally, I wouldn't do it with SSDs. I might do RAID 10, but frankly the speed and reliability of a good SSD is enough that it isn't necessary. I wouldn't do RAID 0 on HDDs either. The chance of failure is so high for such a low gain compared to what an SSD will bring you. You might get comparable sustained reads and writes on RAID 0 HDDs, but access time going from milleseconds to nanoseconds ultimately means SSDs are much faster for most tasks. For VMs in particular, an SSD will definitely outperform 7,200 RPM HDDs in RAID 0.

I agree SSD are the way to go, but cost effectiveness the drives are much better. I can have two 7200rpm drives in Raid 0 and get 1.5-2tb for $150-$200, SSD costs would be double for less space.

MiikeB

WafflesAndRootbeer wrote: »

That product doesn't utilize mSATA. The best you can do on that product is two SSDs in RAID and a third HDD/SSD in an optical bay caddy. Bump the RAM to 32GB and you'll have a monster machine for all your uses, especially if you go all SSD, which you should if you can afford to.

Which product doesn't utilize mSata? The Lenovo W520 has one HD bay, one mSata port and my optical drive which I already have a drive caddy for.

ptilsen

Think about what you're using the space for, though. Games, VMs, OS files and other software? A 512GB will hold it all easily, and 256GB is probably more than enough. Add a single HDD for bulk file storage. With RAID 0 HDD, you basically gain way more space than you should need, lose a ton of performance (maybe 90% for random, 20% for sequential), and lose a ton of reliability (maybe 5x increased likelihood). Plus there's power, noise, weight.

IMO the SSD premium is well worth the trade-off. I fit all my lab VMs in 120GB, and I have a ton of them. Unless you are going to keep 30 or 40 lab VMs on your laptop, I can't imagine a 256GB or 512GB SSD is really going to be an issue. And frankly, if you're labbing that many, I'm guessing you'd be using enough simultaneously to take RAIDed HDDs down to a crawl. I used RAID 0 10,000RPM SAS drives for a while, but eventually relented and put my labs on an SSD. Now I can leave them running while I do anything (e.g. game, encode video) and forget they're there.

sratakhin

I used to keep my VMs on a software RAID-0 with 2 7.2k rpm drives. While the performance was ok, it took almost forever if I resumed more than 2 VMs at the same time. Moved them to a 256GB SSD and don't look back.

WafflesAndRootbeer

MiikeB wrote: »

Which product doesn't utilize mSata? The Lenovo W520 has one HD bay, one mSata port and my optical drive which I already have a drive caddy for.

The Lenovo W520 has two mini-PCIe slots for expansion. In order to use a mini-PCIe slot with an mSATA drive, the slot has to be electrically connected to the SATA controller on the system board. Neither of those slots are.