MrDeference

I am sure most of our sysadmin friends will disagree, but...

"web browsing, some website work, accounts": Don't need a quicker HDD. More RAM, faster CPU possibly...

"databases": for a big DB, SCSI wins.

"vaguely wondering about getting a digital video camera which was the main thought as to why it would need to be faster": Big buffer. High Sequential access. Cheap mass storage. Fast IDE drive.

"stripy RAID helps huge sequential read/writes far more than disc bashing hunting stuff". Depends upon your RAID level. RAID1 is fast at non-sequential reads. RAID0 is extremely fast at sequential reads, but kills reliability (it's not just a 2x thing, reliability is a logarithmic scale). There is a payoff, beyond cost.

"Everyone goes on about SCSI - is it really so much faster in ordinary daily use and why"
Depends what you do everyday. I pick and choose. Being a developer, I am a relatively competent computer user, so am doing a couple of things at a time. One is usually db work, another development or compilation, design etc. This suits SCSI. It's not about outright speed, its about responsiveness.

"Or are SCSI drives generally higher end with lower seek times and better buffers?" They are more expensive, with warranties 5 times longer. They have a more intelligent interface with slightly larger initial overhead. In general it's not worth it for the home user.
HTH.



[Edited by MrDeference - 12/10/2002 11:11:41 PM]

john banks

I presently use a single 7200 RPM ATA100 IDE drive, but I am wondering about something quicker.... SCSI or RAID. Capacity is less important than speed.. I only use about 6GB so far. Would two 30 GB 7200 RPM ATA 100 IDE drives in a RAID configuration double the throughput compared to a single drive? I am basing the system around a P4 2.53 533FSB and 512MB DDR 333 RAM.

Any suggested drive/controller packages welcome. The MB does not have RAID.

super_si

i can recommend IDE raid, striping.

it really is fast. Virus scanning 160Gb took 20mins and im 100Gb full already.

ive being recommended a 4 channel IDE card for £100. Ive being told its very good

Si

MrDeference

Speed for what sort of application? What do you do with your PC?

john banks

Bit of everything really. A lot of web browsing, some website work, accounts, databases, vaguely wondering about getting a digital video camera which was the main thought as to why it would need to be faster (so I suppose capacity and expandability are important after all).

Can't believe that a modern PC still takes the same time as it did 10 years ago to start up! I gather that stripy RAID helps huge sequential read/writes far more than disc bashing hunting stuff.

Everyone goes on about SCSI - is it really so much faster in ordinary daily use and why? I thought ATA100 was underused? Or are SCSI drives generally higher end with lower seek times and better buffers?

Also I usually go for cheap crap when I upgrade my PC and thought I would do it "properly" this time.

[Edited by john banks - 12/10/2002 10:51:17 PM]

shunty

I would agree with the above statements actually.

example: top sales manager/director wants a pentium fast_as_fcuk with more_ram_than_FRED & humongous_hard-drive with every_infrared_accessory......to run INTERNET, WORD & OUTLOOK

I think that analagy sums about 80% of the office staff in the majority of companies, what do you think ??

shunty

chiark

As mentioned, striping will give you performance at the expense of reliability. Lose a drive in the stripe set and you LOSE ALL YOUR DATA. Be aware of that, particularly if you're wanting to keep your videos, pics, whatever...

I'm waiting for a decent cheap IDE controller that has a good implementation of RAID 5 - striping with parity. Basically, one of the discs in the set stores parity, and that's it. YOu need a minimum of three discs. For three discs, you'll only get the usable space of 2, BUT if a single drive fails you can replace and rebuild the set. (If one of the stripe discs fails, the parity information is used to deduce what the bit on the failed disc should be, if the parity disc fails, it just needs replacing and re-syncing)

I'm running 2 identical drives but I wouldn't stripe for reliability, or more accurately potential data loss reasons.

ozzy

Shunty, I'd say that's more like 90% of companies

There's plenty of managers in my work that have nice new Dell P4's with 1Gb of RAM and 100Gb disks that store all their data on the network, run Outlook (with Exchange, so no local data), Word, Excel (for expenses) and IE. Of course, I can justify my own high-sepc PC coz I need to run VNC to manage all the servers and Telnet for the routers

Meanwhile, our Exchange box runs on a dual PIII 550Mhz with 512Mb of RAM and 20Gb of disk space (RAID array) But, hey, that's what happens when a certain company need all the power on the desktop just to run Outlook, Word and IE

Technically a top-spec SCSI system will outperform an IDE one, but with ATA100 the sustained throughput is hovering around that of a SCSI system. Where SCSI comes into it's own is multiuser-based systems i.e. network fileservers, webservers, etc..

Another benefit is reliability. I've spent a lot more time swapping dodgy IDE drives than I have SCSI ones, but I put a lot of that down to PC's getting turned off/on all the time whereas all the servers are left on 24/7. Usually when they are switched off for maintenance and turned back on, the heads would stick and duff-up the drive. You could easily give it a whack with a screwdriver or **cough** drop it from a few feet **cough** to get it spinning again and they would happily run for years afterwards

Just how slow is your P4 system anyway Disk performance does start to degrade if it's running full, but with just 6GB of data I'm surprised you've noticed it.

Web browsing on it's own isn't demanding, but if you've 20 copies of IE running for various web pages, then you'll use most of your RAM. It's worth getting rid of your temporary internet files (set it low, say 10Mb) as this will slow down your PC rather than making browsing quicker with hundreds of MB's of cached pages.

On my home PC's, I set them to 1-5Mb since the broadband connection is fast enough to download web content.

Stefan

ozzy

Nick's point is very important. You need to consider performance over redundancy (what RAID's all about).

If you implement a RAID array with a parity disk (RAID 5), then if one disk fails, you can swap disks and rebuild the array with the minumum of downtime and no data loss.

This is obviously very important for businesses that need servers up all the time. Personally, I can easily rebuild my PC and restore data quickly enough not to need that level of RAID.

But, if you do need raw performance and go with a RAID 0 or 1 setup, just make sure you have good reliable backups.

I'd look at investing in a nice DVD writer, especially if you're also looking at a Digital camcorder.

Have a look at Let's Go Digital for prices of camcorders as they're the cheapest I've seen by far. Then go to your local Jessops (probably Stirling or Edinburgh for you) as they'll price match online stores.

I'm just about to buy a nice Panasonic GVGX7B myself

Stefan

mark_h

RAID1 doesn't help performace when writing to the disk as everything has to be written twice. But it does improve performance of reads.

RAID0 does have another advantage over using the disks as separate drives - you can have one partition the size of the combined disks, rather than two partitions. NT/2000/XP let you combine two (or more) disks into a single partition in another way, called a volume set (the drives are joined such that the partition starts on one drive, and finishes on the other), but this doesn't give any performance gain.

shunty

stephan - that's very technical for this time in the morning mate

shunty

super_si

Whats life expectanty of a striped array then?

Got me worried :S

ozzy

shunty, some of us have just been up for longer

Si, they'll be 3 times more likely to die so I estimate you'll get 6 months tops

Stefan

super_si

Bugger Think im gonna go back to standard IDE then.

DazV

I run a couple of SCSI u160 drives on my developement machine - used for surfing, coldfusion, MySql, 3DS Max, Photoshop.

I've currently got 512MB Ram which is now not enough - the computer has started to use my SCSI as virtual memory which is a real pain (running 3 big apps simultaneously) so the most important thing for me right now regardless of hard disk performance is RAM, which I'll double to 1GB.

I'd be interested to know what capacity RAM other developers on here are running with.

-DV

Barnaby

Striped disks make a huge difference to the overall feel of a Windows (XP/2000) PC. I had striped SCSI disks for a few months and it felt twice as quick as when running a single IDE disk.

The down side with SCSI in my opinion is the noise. The disks I had sounded like aircraft engines spooling up all the time. Wouldn't be a problem at work, but not much fun at home.

DV - I run 1GB as a minimum when developing. But then I tend to open a lot of applications at once and don't like it to swap.