SCSI hard drive in workstation - good idea?

[GrefMofovich]

Hi, I'm looking to build a high-end but pretty standard Win XP comp and wondering if the time has come to go scsi for the c: drive.

Main concern = how to make programs load faster, virtual memory to be more effective (or just effective, period ) and large files to save/open faster.

The two models I'm looking at are the 80GB Barracuda IV ($95) and the Seagate Cheetah SCSI 36.0 GB Model# ST336607LW -X10 ($157 plus adapter cost @ newegg.com) The scsi seems to be superior in every respect - 10k rpm vs 7200, 8 MB cache vs 2 mb, lower seek time and faster throughput (so I've read).

As I said the motherboard has no onboard scsi, nor am I planning to use RAID of any sort. Incidentally would it be better performancewise to get a mobo with on-board 80 pin scsi (I know it would be much less cost-effective)

I've considered SATA but have heard the it's mostly designed for RAID... Edit- my mistake, I meant to say my info states that the 7200 rpm version wouldn't be much better than IDE except in RAID!

Any input is appreciated!

-GM

[Mm9004]

SCSIs are expencive, just go to newegg and look at their SCSIs they should be at least $250 for a 74GB model.

Frankly, I wouldn't trust something so cheap uless you knew exacticly what HDD they're talking about. And then employ caution in case they're second-hand.

You're pretty much correct about the SCSI being the way to go. Although, if you want to make it worth, you must get a high-quailty SCSI because the WD raptor is just as good as a medium-quailty SCSI drive; plus it costs 30% less. The current capacity for the Raptor is 36GB but they plan to make a 74 this month so dont get hung on size. If you truely want a SCSI you musty either make it a High-quality drive or tell yourself that you absolutly need a SCSI or you will die from lack of power. Good luck.

[bassman]

A SCSI drive will perfectly fit the needs you mentioned. If the motherboard you elected hasn't got SCSI support simply get an adapter card and enjoy the (great) performance benefits of the SCSI interface

[dajogejr]

Originally posted by GrefMofovich


btw I've already decided against SATA as I have heard it's mostly designed for RAID...

Wrong...wrong...wrong.

It works fine standalone, or with RAID.

The only SATA I'd consider using, if I were you, is the Western digtal Raptor.
Reason being, I dont' think the standard 7200 RPM drives are much different in performance versus the IDE drives.

But...at 10K RPM of one of those, coupled with a 8MB Cache...I love mine.

It works just fine by itself...no need to RAID.
The RAID theory is based on data redundancy...and/or speed....

Just about any review you read, will say the Raptor, although in theory is for servers in RAID config, it actually is ideal for desktop computing. speed and a 5 year warranty...pretty darn good.

It won't be quite as fast as a full blown SCSI setup...but, then again...it won't nip at your wallet as much, either.

Most new, high to mid end motherboards are adapting to SATA technology. Can't say that for SCSI....yet!!!

[urdvurk]

I wouldn't necessarily go for the SCSI solution. ATA and SATA are quite fast, so unless you get a U320 SCSI setup there won't be much in it performance-wise, and that's without considering the difference in price.

You might also consider getting a number of smaller disks, put your Windows and apps on one, your data on another, maybe your temp files on a third, so as to make sure to fill the available bus bandwith as much as possible (be it IDE or SCSI) whenever there's a lot of traffic. Also you can keep fragmentation down quite nicely that way. If you want speed, don't use one large disk with multiple partitions. Whenever two partitions are read from / written to at the same time, they will share the bandwidth of the physical disk, effectively halving it.

[Peter M]

There's quite a noticeable performance delta - maybe not in the datasheets, but in real life. Point being that linear throughput in IDE drives tends to drop massively as the drives fill up, not so with SCSI. The latter also have substantially lower seek times and access latency, particularly in multitasking or just multi-threaded high load situations. This is because SCSI drives can work on multiple requests at the same time, and complete them in any order; IDE is fully sequential.

Let's not get started about the massive difference in reliability.

So, GM, if that's going to be a serious WORKstation not a performance toy, go SCSI. For a single drive, an U160 controller will be sufficient - the best drives currently are at about 85 MB/s and just below 5 milliseconds access time.

[GrefMofovich]

Excellent! This is the drive I'm deciding on going with:

Seagate Cheetah
Model#: ST336607LW
Size: 36 Gigabytes
Interface: SCSI 68 Pin Ultra320
Seek time: 4.7ms
Transfer Rate: 320MB/Sec
RPM:10,000
Cache: 8MB
Warranty: 5 Years

Thank you all for the advice. I'm really starting to feel at home with this forum now.

Incidentally I've read an article where in some back to back tests the Maxtor Atlas 10k slightly outperformed the Cheetah, but I've had a bone to pick with Maxtor ever since 3 of their 80 gb ide drives pooped out on me. Meanwhile I've been using a Seagate 60 gb for quite some time and it has yet to let me down, so I figure somebody over there has to be doing something right. After losing more than 100 GB worth of data, I'd choose basic reliability over slightly higher speed so I'm staying with Seagate...

-GM

Edit - recently not one but TWO of my acquaintances told me about their maxtor drives giving them trouble from OS corruption to total breakdown. Which leads me to wonder, what is WITH that company??

[Peter M]

Please mind that the 320 MB/s is the interface rate. You're neither going to see that from the actual drive media - and a standard PCI bus won't do more than about 100 MB/s anyhow.

But since the bestest 15000 rpm drives ceiling out around 85 MB/s, that all doesn't matter.

[sm8000]

What kind of SCSI card are you looking at?

[bassman]

Originally posted by GrefMofovich
Thank you all for the advice. I'm really starting to feel at home with this forum now.

That's is really nice to hear!

BTW, here's a benchamark between SCSI and SATA drives: http://www6.tomshardware.com/storage...chmark_results

[GrefMofovich]

I'm attracted to that LSI Logic ULTRA 160, the first result in the newegg link above by bassman. I know it's no adaptec but I figure I'm never going to need even 50% of a 320 MB interface anyhow, plus it supports 32bit PCI which is what I have, and if 6 out of 7 5-star reviews are an indication of anything, I can't go wrong, especially for the price.

Peter M, I've heard that data transfer in scsi drives is done in "bursts", so what's that about?

Anyway, with this LSI card that according to their specs can do up to 132mb/sec in a 33mhz 32-bit pci slot, I figure I'm covered assuming that the drive indeed won't need more than 85 MB/s bandwidth.

-GM
oh yeah, and if anybody knows a good place to get 68-pin scsi cables, hit me with the link! -thanks!

[Peter M]

Be glad it isn't an Adaptec. From LSI, you get the same performance for half the money - with much better software quality.

64-bit and/or 66-MHz PCI cards always are backward compatible to slower or narrower slots no problem. (The LSI U160 is 33 MHz 64-bit.)

The "bursts" thing goes like that - when a request is being worked on, data travel the interface cable at full interface speed, while the media access inside the drive happens at the drive's actual physical media speed.

This is useful on SCSI because multiple drives can share bandwidth on one cable. E.g. you'll be able to run three or four fast drives on a single U320 channel without losing speed.

Of course, on a commodity mainboard with legacy 32-bit 33 MHz PCI slots, the party's over at around 100 MB/s.

[Peter M]

Oh. The place to buy SCSI gear is hypermicro.com. If you visit storagereview.com beforehand, you might still find their promotion special that gets you the LSI U160 for free when bought with a SCSI HDD from a certain selection of models.

[GrefMofovich]

ok I was having ideas that scsi cables cost > $30 but it seems that hypermicro.com has Three-position Mini DB68(M) flat ribbon cable (TPE - ThermoPlastic Elastomer insulated) url for $9 + free shpping courtesy of storagereview.com. guess that has 2 plugs besides the one that attaches to pci card.

I have had an experience with IDE cable insulation coming off and I assume it was the cheaper PVC insulation, hence I'm thinking of getting the +$2 costing TPE cable.

Edit- As with all posts written before 12 pm, this one was hopelessly confused! The cheetah drive is a LVD drive, so blah-blah, I'm off to get my twisted pair cable...

-GM

[Peter M]

Note that you need an LVD twisted-pair cable with terminator, not the plain straight-wire ribbon cable. The latter is suitable only for Ultra-SCSI and below speeds. U2 and up require the former.

I strongly doubt that Cheetah is an HVD drive. If it is, you're busted. You'll need a (quite rare) high voltage differential SCSI host adapter, not one of today's LVD (Low Voltage Differential) ones.