Utilising SSD and Raid in the same system...

Hello there Peeps!

Intel Quad-core Dell Precision T5400 currently running 32bit windows 7 needs an upgrade to 64bit so as to utilise more memory.

We were thinking of installing the Windows 7 64 bit drive C: on a 128 gig SSD for speed and then installing two-disk sata raid behind that as drive D with two 1TB drives - CAN THIS BE DONE?

Would be very happy if this was the case!

Rgds,

Francois & Sam.

RAID is possible but I would not normally recommend it.

Be aware that there are 2 types of RAID possible with 2 drives. Specifying RAID without the type is meaningless.

RAID 0: The purpose is performance. But while the benchmarks can be quite impressive the benefits in the real world tend to be more modest. There are some serious implications, like if one drive fails you loose everything. There are more besides. Generally RAID 0 is more trouble than it is worth.

RAID 1: All data is written to both drives. This provides redundancy so that if one drive fails you can continue operating and replace the drive at a more convenient time. This is a big deal on a busy server, not so much on a desktop. The downside of RAID 1 is cost, requiring 2 drives to provide the storage space of 1. This is NOT a backup solution. Use it as such to the peril of your data.

There are other types of RAID but they require more than 2 drives. They all have their advantages and disadvantage.

Many people rush into RAID without understanding the implications and only find out later it is not what they expected.

I've run RAID0 with ssd's and hdd's. You get impressive benchmarks. I agree with lmiller that it's generally more trouble than it's worth. that said I do run my OS on a single ssd and storage on a pair of Raptors in RAID0, the Raptors can achieve close to ssd performance.

Raptor HDs with RAID 0 can achieve a high transfer rate but will still not match an SSD. But the real advantage of an SSD is the very low seek time, if that term even has a meaning to an SSD. A good HD seek time will be in the order of 10ms while a high end server HD might be about 4 ms. Over the years seek times of conventional hard drives have slowly dropped but with the laws of physics being what they are there isn't much more that can be done. Seek time for an SSD will typically be <.1ms. Under real world conditions with a modern OS seek time will be far more important.

Edit: It should also be mentioned that SSDs have some advantages other than performance. These include lower power consumption and heat, much greater resistance to mechanical shock, and overall reliability, although there is still much to be done with the latter.

Layback Bear said:

From post #3

Raptors can achieve close to ssd performance

I don't think so.

Think again.
Pretty fast for a spinner, 255mbs and 267mbs compared to a Vector at 295/298mbs



You can raid0 ssd's and get some crazy bench marks but I everyday use I think it felt a bit slower. I replaced the 2 vectors I had in the box with a Seagate 600 480gb (389/397mbs). It appears to preform as well as my 840 Pro.

Edit: It should also be mentioned that SSDs have some advantages other than performance. These include lower power consumption and heat, much greater resistance to mechanical shock, and overall reliability, although there is still much to be done with the latter.

Heat is a big difference in my boxes. SSD's run 2C above ambient and the spinners are 10-12C with the Raptors and 6-8C with lower rpm models.

The benchmark numbers are impressive. But as I said in my post #5 transfer rate has little relevance to real world performance. Conventional drives spend most of their time waiting for the drive head to move to the correct track and the for the platter to rotate to the desired sectors. Only then can data transfer begin. During transfer of any significant amount of data there will be many such delays. Some hypothetical drive could have virtually infinite transfer rate but this would mean little to real world performance.

Having no moving parts seek time for SSDs is very small and rotational delay is a meaningless concept. When data is requested from the drive transfer can begin almost immediately and can proceed with only very short interruptions.

People are often overly influenced by transfer rate benchmarks because they are easily understood. On the other hand seek times (what really matters) are almost ignored because they are more difficult to understand. That is unfortunate.

LMiller7 said:

The benchmark numbers are impressive. But as I said in my post #5 transfer rate has little relevance to real world performance. Conventional drives spend most of their time waiting for the drive head to move to the correct track and the for the platter to rotate to the desired sectors. Only then can data transfer begin. During transfer of any significant amount of data there will be many such delays. Some hypothetical drive could have virtually infinite transfer rate but this would mean little to real world performance.

Having no moving parts seek time for SSDs is very small and rotational delay is a meaningless concept. When data is requested from the drive transfer can begin almost immediately and can proceed with only very short interruptions.

People are often overly influenced by transfer rate benchmarks because they are easily understood. On the other hand seek times (what really matters) are almost ignored because they are more difficult to understand. That is unfortunate.

Thank you Capt Obvious, one question, have you every worked with a fast raid0 and large files, as in gigabytes of video?