raid 0 vs 10k rpm hdd

[coder_t2]

Hey guys, I run SQL Server currently on desktop for work. I want to speed up the I/O some more, and was wondering would 2 7200 rpm hard drives set up as raid 0 be faster than one 10k hard drive? I am thinking yes, but wanted to get your guys' advice.

 

[Rubycon]

Hey guys, I run SQL Server currently on desktop for work. I want to speed up the I/O some more, and was wondering would 2 7200 rpm hard drives set up as raid 0 be faster than one 10k hard drive? I am thinking yes, but wanted to get your guys' advice.

Adding drives does not reduce latency. A 10K drive will have faster access times and allow for more transactions then any 7.2K array would.

If you really want to boost performance put your db on a SSD.

 

[coder_t2]

Yea, I'd love put my DB on a SSD, but the cost is just too high atm. Not to mention everything seem to be like double the price when the company orders it. A 500GB HDD was $80! It's ridiculous.

 

[coder_t2]

So I have been reading up on SSDs and it seems like performance takes a nose dive after a number of re-writes? Is this the case for all of them, or just the cheaper ones atm?

 

[nipplefish]

Drives without TRIM suffer from that problem. TRIM commands ensure that the drive properly clears out deleted data and makes it available. So yeah, mainly older/cheaper SSDs.

RAID0 will have higher overall throughput but with higher seek time. Seek time is going to be the most important factor for a database. My old Raptor averaged about 7ms seek time, while my RAID0 array was more like 14ms. With an SSD seek time is negligible.

 

[Rubycon]

Striping should never increase seek time. If it does I could not measure it let alone see it.

 

[Zap]

So I have been reading up on SSDs and it seems like performance takes a nose dive after a number of re-writes? Is this the case for all of them, or just the cheaper ones atm?

That is indeed the case, but even the cheap ones under "normal" desktop use should last years.

For a database server, you would want to consider drives that are designed for enterprise levels such as the Intel X25-E or any other drive using SLC memory.

 

[nipplefish]

Striping should never increase seek time. If it does I could not measure it let alone see it.

It didn't increase it, that was just the seek time of the 7200rpm drives.

 

[Rubycon]

It didn't increase it, that was just the seek time of the 7200rpm drives.

Right - just to clear that up (when comparing 7.2 and 10k drives).

 

[coder_t2]

Ok good to know. What's special about the enterprise versions of Intel's SSDs? I probably wouldn't use it for what I am doing just because it's a small database, and I am the only one who uses it. I mean, any SSD would make it fly compared to the 7200rpm drive that's in there now. I just finally got a second HDD and was able to put the database files and log files on seperate HDDs, which is supposed to be better AFAIK. I use SQL Server btw.

 

[Rubycon]

Any (non jmicron) MLC drive will work. SLC is expensive and does provide better writes and lifetime if you're writing to the disks 24/7.