Sata/scsi

anon_1245

Just wondering what exactly is the difference between SATA & SCSI and what are the adv/cons of each?

Malafus

Uh, ermm.. SATA and SCSI are completely different.

SATA is generally used in home computers (well, IDE is, but people are beginning to migrate to SATA), whereas SCSI is not. Most mobos do not come with native SCSI support, and you need to purchase an expansion card to use one of these devices. The nice thing about SCSI is that you can daisy chain several devices onto one port.

TBPH, there is no real advantage to SCSI over SATA.
It's slower, more awkward... bleh.

BlueSpud

Malafus wrote:

TBPH, there is no real advantage to SCSI over SATA.
It's slower, more awkward... bleh.

I am not sure this is true. The scsi devices, though more expensive, and slower, are much more reliable than sata and infinatly more reliable that ide. Still overkill for typical home usage. People who cant afford to have down-time use scsi.

7aken

recently had to deal with this debate with an isp who were upgrading servers and were unsure which to use for raid. they decided to go with sata in the end as its more economical. scsi has big advantages over sata however, mainly due to the fact that each scsi hard drive has its own mini computer/controller which is more advanced than those on sata or ide drives. this enables the actuator arm to move less frequently, thus the drive lasts longer. it also means less problems and in the long run- less downtime

the economic issue favors sata however................

Malafus

I was generalising, and considering he asked the question in the first place, I assumed he was a home user with little experience in SCSI. They are far more reliable, but as you say, overkill for a home user. Plus they can be a pain to set up.

egan007

anon_1245 wrote:

Just wondering what exactly is the difference between SATA & SCSI and what are the adv/cons of each?

Read this
http://www20.tomshardware.com/storage/20030501/

stevenmu

Raid used to be a big advantage of SCSI over IDE, it still is if you want large RAID arrays.

blorg

SCSI is generally still faster than SATA, higher performance drives (e.g. 10,000 and even 15,000 RPM) tend to be SCSI although there are a few 10k SATA models out now I believe. SCSI drives tend to be substantially smaller than their IDE/SATA counterparts, this may actually help the SATA performance due to higher data densities (e.g. more data read for a given rotational speed.)

blorg

You almost certainly do not need SCSI unless you are running a highly-trafficed server, and SATA is a lot easier to set up and manage. What is the application?

SouperComputer

in terms of bus bandwidth: SCSI and SATA are near enough each other. However a top end SCSI drive will bury a top end SATA.

Also, SCSI generally uses a lot less CPU time, also a factor to consider.

SCSI isnt "needed" unless you are going really high end, but the difference is noticeable on a desktop.

I switched from SCSI to SATA (with raptors) and I have since gone back to SCSI. Overall it performs much better, regardless what benchmarks show.

uberpixie

SouperComputer wrote:

in terms of bus bandwidth: SCSI and SATA are near enough each other. However a top end SCSI drive will bury a top end SATA.

Also, SCSI generally uses a lot less CPU time, also a factor to consider.

SCSI isnt "needed" unless you are going really high end, but the difference is noticeable on a desktop.

I switched from SCSI to SATA (with raptors) and I have since gone back to SCSI. Overall it performs much better, regardless what benchmarks show.

What are you using your pc for that you need scsi for?

Or do you just perfer them for general performance?

SouperComputer

LOL my PC at the moment is pretty slow: 800Mhz Slot A, 256, 32Mb onboard Riva TNT 2, then of course a 76Gb SCSI drive.

I dont "need" SCSI, but since trying it out four years ago, ive found the switch back to ATA hard. Even using raptors.

I have a storage server that does the bulk of the storage for the network. On the PC I am using about 18Gb for windows and 15 for Linux, so even with 76GB a lot of the space is wasted.

anon_1245

its for a small server here in the office. basic filesharing and backup. will be running linux. Files average between 10mb to 100mb. There will be about 5 clients with their data going on it every evening.

Ill attach the spec of the machine, ill want to add another about 300gb hard disk onto this aswell. Will it go in without problems?

Thanks for your help so far guys.

SouperComputer

anon_1245 wrote:

its for a small server here in the office. basic filesharing and backup. will be running linux. Files average between 10mb to 100mb. There will be about 5 clients with their data going on it every evening.

Ill attach the spec of the machine, ill want to add another about 300gb hard disk onto this aswell. Will it go in without problems?

Thanks for your help so far guys.

TBH, you could do what you need with a PII 266/128Mb RAM, using a GB NIC! SCSI is not going to be an advantage for your as it just really a file server. If you had databases on there that were being hammered by a lot of users, that would be another story. The performance bottleneck is going to be your NIC and or the PCI BUS, not your HD's.

Dont bother with SCSI anyway, if you have another machine in the network that you can decommision, you can use it as a server, all you need is:

1. SATA or PATA PCI RAID card (adds RAID and overcomes the BIOS HD size limitations for older computers)
2. 2x whatever capacity (mirror em for fault tolerance) HD's, seagate seem to be most reliable and give the longest warranty)
3. Good airflow over the HD's! (important for life, keep HDA temp <40C)
4. A 1Gb NIC (cheap enough on komplett)
5. Ideally a switch with a 1GB uplink.

This setup will probably cost you under €500, with which you have more storage, redunancy for HD failure and a few bob in you pocket!

Clarkconnect is a good distro for this kind of setup.

Ive used this kind of setup for others and indeed my own office without any probs. In the office, at any given time there could be 5 or 6 users burining DVD's, copying multi-Gb ghost images etc with no probs.

The money on the machine you have specced would be better spent on the above setup and some GB switches\NIC's

that's my €0.02 anyway!

Unless you forsee the demands of this network going through the roof in a while, a very low spec machine will do the job without even breaking a sweat!


[edit] actually, Komplett have some St Labs 8port 1Gb switches that are cheap and cheerful (€80 or so), if all the machines are trying to copy info at the same time, it might be a good plan to put 1Gb nics in all the machines to help things along[/edit]

anon_1245

yeah, Ill check that out. Thanks Souper!