Introduction

Storage sits at the heart of every system, from a notebook right up to a rack filled with servers. It wasn't long ago that a hard drive was a fairly expensive component that offered significantly less capacity than the massive drives available today. Today, the IT consumer has to decide between SATA/SAS/Fiber Channel, and sizes ranging from 36GB up to 750GB (SATA). But perhaps the most interesting transition that has occurred in the enterprise storage arena in the last few years is the impact that the desktop market has had on the direction of the enterprise storage market.

A few years ago, the enterprise storage market was SCSI or Fiber Channel. If you wanted a chassis full of drives in a DAS (direct attached storage) configuration or in a SAN (Storage Area Network), it came with SCSI or Fiber Channel drives. At the time drives started at 9GB and topped out at 74GB and connected to an Ultra160 SCSI interface, or possibly a 2Gbit Fiber interface. Below is an excellent image from IBM (courtesy of StorageReview), that details 15 years of history for the hard drive.


The evolution of today's IT storage

The desktop market has been driving storage higher and higher every year, which of course impacts the IT market, since IT has to back up those drives. Now the enterprise is full of SATA offerings for near-line storage, and even in some more expensive SAN products like EqualLogic. SATA offers decent performance for long term storage and even some small to medium sized back-end applications. However, it can't compete with the latest evolution in high-performance storage for the IT market, SAS (Serial Attached SCSI).

Serial Attached SCSI was introduced into the IT storage market in 2004, and has been growing exponentially every year. We are now at a point where Parallel SCSI is starting to fade very rapidly, with most new servers using SAS instead of Parallel SCSI. Even though there was a specification for Ultra640, most manufacturers skipped right over it and adopted SAS as the next SCSI evolution.

Basic SAS Architecture
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  • yyrkoon - Friday, February 2, 2007 - link

    When are you guys going to do some reviews on consumer grade equipment ? Well, let me clarify, 'consumer grade' with on card RAID processor(s). For instance,, right now, I'm in the market for a 8 + port RAID HBA, but would like to know if buying a Highpoint 16 port SATA RAID HBA, would really be any worse than getting an Areca 8 port HBA, for ~$200 usd more. 3Ware, from what I understand offers the best Linux/Unix support, or does it ? If so, would it really make much of a difference in a SOHO application ?

    I personally, would like to see a comparison of the latest Promise, Highpoint, Areca, 3Ware, etc controllers. In short, there is a lot out there for a potential buyer, such as myself, to get lost in, and basically, I personally am interested in reliability first, speed second (to a point).

    Anyhow, I just thought I'd point out, that while you guys do cover a lot in the area, you guys seem to have a gap, where I think it really matters most to your readers (home PC / enthusiast crowd/SOHO).
  • mino - Saturday, February 3, 2007 - link

    I would stay away from Highpoint.
    We have had several issues of RAID HBA(new one!) consistently going down AND screwing the whole RAID5 ubner some workloads. For the money one is better off with QuadFX ASUS board than to go Highpoint-like solutions.
    Areca is pretty much on a different level, ofcourse...
  • yyrkoon - Sunday, February 4, 2007 - link

    Again, this only reinforces what I've said, need a good article on which HBAs are good for reliability, etc.
  • mino - Sunday, February 4, 2007 - link

    Any 3Ware, Areca, LSi, Adaptec solution should be just fine.

    Most people do not actually need RAID5 for home usage and it is usually cheaper to go _software_ RAID1 with every drive in the RAID attached to different controller. In such a scenario even the cheapest or onboard controller offers comparable fault-tollerancy to high-end RAID% solutions.

    However the simplest way to go is really 2 NAS RAID5 boxes mirroring each other.
  • dropadrop - Tuesday, February 6, 2007 - link

    quote:

    Any 3Ware, Areca, LSi, Adaptec solution should be just fine.


    I would rule out Adaptec and the older LSI chipsets still available (under several brands like Intel for example). We replaced a bunch of Intel 6 & 8 port controllers with top of the line 8-port Adaptec SATA II controllers.

    The performance of the Intel controllers (with LSI chipsets) was terrible. We got about 8-13MB/s sequential writes with RAID 10 arrays, and tested using alot of differant drives. The Adaptec products are alot better in regard to speed, but keep dropping drives. This seems to be a common problem, but they have no solution.

    I've previously used 3ware without any problems, and would gladly test Areca if they where available here.
  • yyrkoon - Sunday, February 4, 2007 - link

    why would I want to spend 1300 usd + per 5 disk array (minus drives), when I could build my own system much cheaper, and use the hardware/software I wanted ? Just because I don't know which HBAs are more reliable, than others (because I obviously cant afford to buy them all), doesn't mean I'm an idiot ;)
  • Bob Markinson - Friday, February 2, 2007 - link

    Interesting review!
    I would have liked to see a comparison with latest gen 15K SCSI drives and not 10K SCSI drives to see the true SAS interface performance advantage over SCSI. Futhermore, the Serveraid 6M comes in two versions - one with 128 MB cache and the other with 256 MB cache. Also, there were performance issues with early 7.xx firmware/sw revisions on the 6M at high IO loads - hopefully you ran the tests most recent firmware. Write-back cache was enabled on the 6M, right?

  • Lifted - Tuesday, February 6, 2007 - link

    Based on the title of the article, Promise VTrak J300S, you are expecting too much. The "comparison" was more like an ad for the product. What is point in comparing 10K U320 vs 15k SAS? It's supposed to tell us what exactly? You clearly need to look elsewhere for a SAS vs U320 comparison if that's what you were expecting here. This was more for kicks I think, and perhaps to make the J300S look better than ____ ??? I don't get it, it's just a storage enclosure. The RAID adapters and drives are what determine performance, so why was this apples-to-oranges "performance" review thrown into an enclosure article?

    Odd, quite odd.
  • fjeske - Friday, February 2, 2007 - link

    Isn't it a bit unfair to use old IBM 10K SCSI drives in this comparison? None of the now Hitachi drives show good performance on Storagereview.com. Compare to Seagate's Cheetah 15K.5 and I think you'll see a difference.

    Also, how was the SCSI setup done? Attaching 12 drives to one U320 bus will obviously saturate it. Servers usually pair them when connecting this many drives.
  • cgaspar - Friday, February 2, 2007 - link

    SAS and SCSI drives have disk write caches disabled by default, as the drives' caches are not battery backed. IDE and SATA drives frequently have write caching enabled by default. This makes writes much faster, but if you loose power, those writes the drive claimed were committed will be lost, which can be a very bad thing for a database. I'd suggest disabling the write cache on the SATA drives and re-testing (if you still have the gear), I suspect the results will be illuminating.

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