SQL Server Performance Forum – Threads Archive

SAS vs SCSI

I’m looking to purchase an external drive system for my .mdf files (want to increase read performance). Can anyone provide advice on which option will provide better performance? 1. MSA50 dual channel with 15k U320 drives (5 drives per channel) 2. MSA30 with 15k drives (5 drives per channel). Acually, I’m not sure how to configure the chanels on SAS. Any help with would be greatly appreciated. Thanks!

the MSA 30 is U320 for 3.5in drives, which can be either 10K or 15K the MSA 50 is SAS for 2.5in SFF drives, which are only 10K 15K drives can achieve slightly better performance in transactional apps operating at low queue, but in a properly designed storage system,
this really should not make much of a difference the other issue is the SAS SFF drives are more expensive than the 3.5in drives, (10K 73GB) long term, SAS is the preferred solution, but nothing wrong in going with U320 for now. no config issues on SAS

Thanks Joe. That’s very helpful.

I noticed that HP 72GB 15K rpm SAS disks now are available. I will go for dual P600 controllers with 512MB cache to dual MSA50 with 8 x 72GB 15K rpm disks in each. Will use Raid 0+1 for speed. Haven’t decided as yet how to configure the raid arrays (oh, there is a P400 in the HP DL585G2 with another 8 x 72Gb 15Krpm disks. I thought
2 disks for OS
2 disks for tempdb
2 disks for logfiles
the rest for DB Comments and suggestions welcom Tom Tom

i think the 15K SAS are only LFF (3.5 in) which should fit in the unreleased MSA-60
the SFF (2.5in) only offers 10K depending on the app, i prefer 2+ disks for logs, ie, depending on the size of T-Log backups, and tolerable performance impact during T-log b/u i also prefer tempdb shared with data, for maximum performance on need for non-clustered systems, the OS drive could also be used for logs if desired
clustered must have dedicated OS drive, unfortunately SAS does not support clustering yet (from HP Dell?.

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