Can RAID disks be faster than SSD?

[Craig234]

Someone told me he measured his two disks in raid and found theywrite at 250MB/sec, faster than the SSD listed performance of 180MB/sec.

Does this sound reasonable?

I am not that familiar with either to sanity what he's seeing.

 

[masteryoda34]

How about access times?

 

[Blain]

The devil is in the details
* There are lots of mechanical drives.
* There are also plenty of the "SSD" around.

Toss us some specific details...
1. What HDs (specifically) was your pal using?
2. What RAID controller was your pal using?
3. What benchmark utility did your pal use?
4. Specifically, what model "SSD" are you referring to?
5. When comparing HDs in RAID 0 against a SSD, are you only concerned about a single benchmark result?

 

[pjkenned]

Two disks it is harder... however here is my cheap SAS setup that was 600MB/s-700MB/s using cheap (<$40 each) 2.5" 15k rpm SAS drives:
http://www.servethehome.com/?p=32

Between the 8 small platter disks at 15k rpm, in most of my use cases it was faster as an OS drive than the Vertex is. It should be noted these were the cheapo first gen 2.5" SAS drives, not the newer ones which are much faster. I have since moved the entire setup to my Win 2k8 server with other raid arrays. Also, the drives and the Adaptec card have so much cache (BBU on the card) that small transfers were never an issue. Anything over 512MB was likely a sequential read/write, anything smaller seem to have gotten sucked up into the cache. Small reads are better on the Vertex.

There are advantages to both SSD's and spindle drive RAID though. I do have a feeling that as flash prices continue to fall, this won't be the case for long.

 

[Syntax Error]

In throughput? Yes, a RAID array can thoroughly beat a single SSD. In access time? Never in a million years.

Now, if you want real performance, try RAID'ed X25-Es. :Q

 

[jimhsu]

Theoretically RAIDed hard drives can beat any kind of storage in all parameters. Need lots of IOPS? Simply get a thousand hard drives, several dozen racks, and a nice thermally controlled room. Practical? No, except for the largest operations (like Google). SSD deliver the IOPS while vastly simplifying the logistics, making them quite attractive for enterprises.

Then again you have things like this (5 MILLION IOPS) that smack thousand disk hdd arrays so bad it's not even funny.

 

[Idontcare]

Originally posted by: jimhsu
Then again you have things like this (5 MILLION IOPS) that smack thousand disk hdd arrays so bad it's not even funny.

Insane. Can my system memory even do that?

 

[tcsenter]

Originally posted by: pjkenned
Two disks it is harder... however here is my cheap SAS setup that was 600MB/s-700MB/s using cheap (<$40 each) 2.5" 15k rpm SAS drives:
http://www.servethehome.com/?p=32

Where did you buy Savvio 15K SAS drives for less than $40 each? :Q

 

[pjkenned]

The two times I've done it I did ebay and craigslist. 36.7GB drives are super cheap.

Also, insane IOPS aren't really needed in desktop environments that much. IOPS have traditionally been a server benchmark for a reason. Then again with 12GB of desktop memory these days, once stuff loads you don't hit the disk much.