Not sure if SMP is for you? Here’s a cheap way to find out…

[Kingslayer]

I was told the same thing. Don't buy that BP-6. Once you go dual you'll never go back. You'll be wrapped up in hella expensive computers from now on.

YEP!

But the ability to watch your friend, who just bought a brand new P4 2.2 system wrench his face in disgust when you burn a CD and surf at the same time because he cant is priceless.

I also love the arguements on what's harder to overclock AMD's or Intel's. I tell them this. You haven't lived until you overclock duallies. It's...well...twice the adventure. And I don't care if you overclock AMD or Intel duals.

 

[donny_paycheck]

Ok, so I'm thinking of trying this out, but I'm a bit confused by the processors.

I know that PIII is generally preferable to PII, but I don't get the whole Xeon thing. WHat's a Xeon? Would I be better with a PII Xeon or a regular PIII at the same clock speed? And why are Xeon prices all over the map on pricewatch?

I'd be happy if someone just wanted to post a link to some info as I'm sure this is a real newb question.

nihili

A PIII Xeon processor cartridge is about twice the physical size of a regular PIII because of the L2 cache. The PIII Xeon has a CPU core nearly identical to the PIII with only the addition of a small amount of SMP instructions. The big difference is a monster-sized L2 cache (256k, 512k, 1mb and 2mb) that runs at processor frequency instead of a division of it. The ones that you see that are horrendously expensive on Pricewatch are the ones with a large cache. They also require a slot-2 motherboard, which is pretty expensive in it's own right. I got the parts for my system on ebay for a lot less. They're not overclockable at all; none of the slot-2 motherboards have FSB adjustments and obviously the multipliers are locked. Maybe if you hacked the clock generator IC on the motherboard you could, but I'll leave that to the electronics gurus.

Xeons are sweet for SMP because they can also be scaled up to 8-ways, not just duals. You can find 4- and 8-processor Xeon systems on ebay also, but of course they're expensive. They are extremely fast for their mhz when performing multiple tasks because of their large caches.

Safely said, a PII or PIII Xeon is the same CPU as it's non-Xeon brother but with a large cache that runs at full processor clock speed. It's not my main system, but my the PIII Xeon in my sig will run circles around my overclocked XP 1800+@1800mhz when it's got many different things running.

 

[nihili]

Ok, let's make sure I've got this. Order of preference would be...

PII, PII Xeon, PIII, PIII Xeon

Non-Xeons are slot 1, Xeons may be either slot 1 or slot 2.

So, if I pick up a duallie PII for cheap, I could in theory upgrade it to PIII Xeons as long as I stuck with slot 1 Xeons.

Is this roughly right?

nihili

 

[donny_paycheck]

Ok, let's make sure I've got this. Order of preference would be...

PII, PII Xeon, PIII, PIII Xeon

Non-Xeons are slot 1, Xeons may be either slot 1 or slot 2.

So, if I pick up a duallie PII for cheap, I could in theory upgrade it to PIII Xeons as long as I stuck with slot 1 Xeons.

Is this roughly right?

nihili

All Xeons use the slot-2 form factor so the regular PII/PIII and it's Xeon equivalent are not interchangeable.

I would also prefer a PII Xeon with a large cache (2mb) over a higher clock speed PIII, but this is arguable. A PII Xeon and a PIII would probably cost about the same; the Xeon perhaps a tiny bit more ($20). Initially I had PII-450mhz/2mb Xeons in my system, which I found on ebay for $50 a piece. Upgrading to the 733mhz PIII flavor would have cost beaucoup bucks but I traded my old PII versions and some LVD SCSI drives with my friend for the PIIIs.

 

[DSTA]

every dual setup needs one of those things? VRmS?

Nah. It's just a feature of many of the workstation class machines Colin talked about in his initial post (HP Kayaks, Compaq Pro WS...). Problem is the VRMs are not easy to find separate and buying them as spare from Compaq or HP would cost many many times more than the very fair price Donny is asking .

That said, almost all dual boards you can/could buy retail have VRMs on board for both CPUs.

 

[donny_paycheck]

Here is a picture of a Gateway quad-Xeon motherboard that requires VRMs. The VRM sockets are boxed in red. There is one for each processor but I do not know what the additional fifth is for. My system only needs two and not three, but only one if just a single CPU is used (which can be done with a terminator card in CPU2's slot).

 

[Cowboy Shane]

Originally posted by Ice_Gargoylle
There is a myth that in order to run multiple CPU's, they need to be the same stepping and cache size. This is not true.

On an Abit VP6 this is true. If you mix stepping on the CPU's, the voltage will drop to 1.2 for each of them and it will not work. This kind of issue is dependant on the board, so it pays to research before plonking down your money

 

[donny_paycheck]

Bump...for all the newer members who are wondering about SMP...

 

[SickBoy]

Yes, yes, excellent read... using a dual PII Xeon (and now a dual PIII Xeon) at work was what got me hooked on SMP.

 

[armatage]

I have bought 2 PII 233MHz CPUs, a TNT2 32MB GFX card and dual slot 1 mobo off of eBay. I will be getting ECC DIMMs soon but at the monent 256MB PC133. Will be running Win2K and I will get Win2K Server soon.

I was just wondering if there is anything to watch out for.

What about benchmarking, will SiSandra cope with dual cpus?

My main rig is an XP 1700 (1.551GHz), Gforce 2 TI, 512MB PC2700 mem and I was wondering how the two will compare?

I will soon start folding 24/7!

 

[donny_paycheck]

I was just wondering if there is anything to watch out for.

Watch out for? No, you shouldn't need to look out for anything as long as you're doing a clean install. Win2k doesn't detect 2nd CPUs when added later unless you adjust something, but you shouldn't have any problems. This is all I can think of.

What about benchmarking, will SiSandra cope with dual cpus?

Just make sure multi-threaded benchmarks are enabled. See picture attached.

My main rig is an XP 1700 (1.551GHz), Gforce 2 TI, 512MB PC2700 mem and I was wondering how the two will compare?

This comes up a lot. I suggest you read diehrd's sticky in this forum about it. I'll tell you what I've seen, though. For gaming, the XP will blow the P2 away. In all single-threaded tasks it will, in fact, provided the task is the only task running. The best way I've found to look at it is that duals are no faster than their single-CPU counterparts at one, single-threaded task. However, duals are more robust. The P2 dual will do one thing as fast as a single P2, but load it up with two or more tasks and it will still go as fast as a P2. The single Athlon, on the other hand, will slow down quickly as the apps fight for CPU cycles. Hopefully this makes sense...

 

[SickBoy]

I have bought 2 PII 233MHz CPUs, a TNT2 32MB GFX card and dual slot 1 mobo off of eBay. I will be getting ECC DIMMs soon but at the monent 256MB PC133. Will be running Win2K and I will get Win2K Server soon.

I was just wondering if there is anything to watch out for.

What about benchmarking, will SiSandra cope with dual cpus?

My main rig is an XP 1700 (1.551GHz), Gforce 2 TI, 512MB PC2700 mem and I was wondering how the two will compare?

I will soon start folding 24/7!

Well, a dual PII 233 system isn't going to knock your socks off compared to your single CPU rig but it WILL be surprisingly usable depending on how much RAM you put in. Dual systems need an honest half gig to really shine IMHO.

Outta curiosity, what chipset is your board? If it's BX, you might be able to go as high as dual PIII 800's or even higher. Also be on the lookout for SMP capable slockets if you think you might want to upgrade CPU's later on.

As far as OS, Win2K Pro has support for dual CPU so unless you _need_ some of the extra server-oriented features in 2K Server, don't bother.

sb