I've been reading a few of the threads for new PC's and it got me thinking...

Excuse the noob enquiry.

LFS has been written to work on single core chips.
Does that mean if I buy a quad core PC that 3 of those cores are doing diddly squat?

I'm looking to upgrade from an athlon 3000xp with a 7900xt 128mb and 1gb ram.

I'm not playing any other games or dvd burning etc etc. This will be purely for LFS.

The bottom line is this, at what point, do you draw the line in terms of processing speed. Do I buy the fastest single core Intel or AMD because everything beyond that is surplus and a waste of money or just go and get a quad core and be done with it?

BTW how much faster is the slowest Quad over the fastest single core in terms of LFS performance?

Tis all a tad complicated for my liking.......

Andrew

If you buy a quad core PC, those 3 other cores will do 'diddly squat' in LFS. Maybe not for other tasks outside of LFS, but LFS only uses one core. Maybe four cores would be useful for other things, but not for LFS.

@hrtburnout.. that's illuminating, thanks. So does that mean that a quad core 2.33Ghz is less useful to run LFS than a 3Ghz P4, for example?

What seems to have increased markedly since P4 days is mobo FSB speed, from 800ish up to 1333 now (I think). does the increase in the general data flow around the memory/ mobo that you'd now be getting with a quad core system make up for the fact that the single core running LFS is actually slower than the ancient P4? (actually, in my case, AMD2800+XP/333).

on separate postings, http://www.lfsforum.net/showthread.php?t=31380 a system around £400 is proposed. Dual core. I've poked around on overclockers.com (the source for the prices in that thread) and found that quad core is only £20 dearer (ish). So it would seem churlish not to have it...

Even a AMD 3800x2 is faster than your 2800+ using just one core. The increased memory bandwidth secures that the cpu is getting data to process. By the way I can´t think about using a quad core cpu nowadays without wasting money. What you´re up to ? Watching HDTV + Downloading + Playing LFS + Converting Videos... at the same time?
Go for a dualcore, Coreduo 6550-6750, it will be sufficient. By the way the quad will need more power.

Quote from wobbly_rider :

@hrtburnout.. that's illuminating, thanks. So does that mean that a quad core 2.33Ghz is less useful to run LFS than a 3Ghz P4, for example?

Nah...

Quote from wobbly_rider :

What seems to have increased markedly since P4 days is mobo FSB speed, from 800ish up to 1333 now (I think). does the increase in the general data flow around the memory/ mobo that you'd now be getting with a quad core system make up for the fact that the single core running LFS is actually slower than the ancient P4? (actually, in my case, AMD2800+XP/333).

Without going into detail, the new architecture is much faster than the old P4 architecture, for example a dual core P4 3Ghz doesn't come close to a Core 2 Duo 3Ghz. Wikipedia has a lot of information if you wish to learn more about it.

In the short term a faster dual core would probably be the best bet, however in the longer term, with more applications and games becoming multithreaded, I guess more cores is better.

Quote from pb32000 :

In the short term a faster dual core would probably be the best bet, however in the longer term, with more applications and games becoming multithreaded, I guess more cores is better.

Add onto that that whilst running a single-core app like LFS your other cores could be performing 'background' tasks that would either impact LFS or have to be closed in some cases for performance - e.g. enhanced drivers/utils, AV, Firewall etc...

Since I got a Core2Duo the multi-tasking/alt-tab performance of my system has gone up dramatically over a P4 HyperThreader. Just because LFS doesn't use multi-cores right now don't forget LFS, even with focus, will not be the only thing your system will need CPU time for.

Quote from Monkeymike :

Add onto that that whilst running a single-core app like LFS your other cores could be performing 'background' tasks that would either impact LFS or have to be closed in some cases for performance - e.g. enhanced drivers/utils, AV, Firewall etc...

Since I got a Core2Duo the multi-tasking/alt-tab performance of my system has gone up dramatically over a P4 HyperThreader. Just because LFS doesn't use multi-cores right now don't forget LFS, even with focus, will not be the only thing your system will need CPU time for.

Thanks for that, didn't think of that at all:doh:
So now I'm in the same boat as everyone else..........
trying to get the fastest system for my budget (whatever that is)

Do what jakg does, he bought his quad core, and has 3 copys of LFS running for replays, and 1 that he's using, just to make him feel like he's using all 4 cores.

Myself, I encode video on 1 core, and LFS on the other core (2.16 GHz, Core2Duo T7400 (mobile Core2Duo))

TBH on a single threaded CPU Single to Quad cores makes all of about 4% diffence, because Windows at idle only uses about 3-5% CPU.

Of course, imo you'd be a fool to buy a Dual when a Quad is the same price, but that's just me.

I'd look into a Dual Core simply because the fastest single cores (that are Currently out - the Conroe-L could change this via overclocking) are the 2.8 GHz AMD's on Skt. 939.

For reference - in a single threaded benchmark (ie one that uses only one core), my old CPU, a 3 GHz AMD, got 27 seconds (This is SuperPi, calculating one million digits of pi - lower=better). My 2.13 GHz Quad got about 23 seconds at stock speeds, and when i took it to 2.8 GHz it was setting 18 second times.

Even if your not a multi-task whore, then a Dual Core will still give you the best performance.

How much do you have to spend?

EDIT - Dustin, i'm wierd - i didn't buy this Quad for multi-tasking, i bought it because A. It was cheap and B. Because for multi-threaded stuff (ie Rendering) it will pwn. TBH i think this whole "Scan your PC for Viruses while checking your email, encoding a video, downloading pron and playing LFS" thing is just a gimmick...

Quote from Jakg :

TBH on a single threaded CPU Single to Quad cores makes all of about 4% diffence, because Windows at idle only uses about 3-5% CPU.

Of course, imo you'd be a fool to buy a Dual when a Quad is the same price, but that's just me.

I'd look into a Dual Core simply because the fastest single cores (that are Currently out - the Conroe-L could change this via overclocking) are the 2.8 GHz AMD's on Skt. 939.

For reference - in a single threaded benchmark (ie one that uses only one core), my old CPU, a 3 GHz AMD, got 27 seconds (This is SuperPi, calculating one million digits of pi - lower=better). My 2.13 GHz Quad got about 23 seconds at stock speeds, and when i took it to 2.8 GHz it was setting 18 second times.

Even if your not a multi-task whore, then a Dual Core will still give you the best performance.

How much do you have to spend?

EDIT - Dustin, i'm wierd - i didn't buy this Quad for multi-tasking, i bought it because A. It was cheap and B. Because for multi-threaded stuff (ie Rendering) it will pwn. TBH i think this whole "Scan your PC for Viruses while checking your email, encoding a video, downloading pron and playing LFS" thing is just a gimmick...

Thanks Jack, its not really a question of budget, it was more of understanding what is actually required. If a quad core didnt actually make that much difference, then why buy one?
However, now you and previous posters have explained, it is worth while upgrading to a c2d or quad core, purely because LFS isnt the only application running. Now it makes sense to buy the fastest you can afford.......what ever that may be.

Thanks for your help

Andrew

Quote from mrfell :

Now it makes sense to buy the fastest you can afford.......what ever that may be.
Andrew

True, but I'd say there's a threshold at about £200 for CPUs atm, anything over that and the prices increases rapidly for little performance gain, and that gain can be acheived by overclocking a cheaper CPU.

Quote from Jakg :

TBH on a single threaded CPU Single to Quad cores makes all of about 4% diffence, because Windows at idle only uses about 3-5% CPU.

Of course, imo you'd be a fool to buy a Dual when a Quad is the same price, but that's just me.

I'd look into a Dual Core simply because the fastest single cores (that are Currently out - the Conroe-L could change this via overclocking) are the 2.8 GHz AMD's on Skt. 939.

For reference - in a single threaded benchmark (ie one that uses only one core), my old CPU, a 3 GHz AMD, got 27 seconds (This is SuperPi, calculating one million digits of pi - lower=better). My 2.13 GHz Quad got about 23 seconds at stock speeds, and when i took it to 2.8 GHz it was setting 18 second times.

Even if your not a multi-task whore, then a Dual Core will still give you the best performance...

Does that also apply against the fastest intel single core chips?

The fastest intel single-core chips were old P4's - AMD had them beat back then, and the new Core 2 CPU's (which freaking rock btw) only come in 2 and 4 core versions.

Quote from Jakg :

The fastest intel single-core chips were old P4's - AMD had them beat back then, and the new Core 2 CPU's (which freaking rock btw) only come in 2 and 4 core versions.

Cheers for the help.
Much apprieciated

Quote from Jakg :

The fastest intel single-core chips were old P4's - AMD had them beat back then, and the new Core 2 CPU's (which freaking rock btw) only come in 2 and 4 core versions.

Aren't the new celerons conroes?

They aren't out yet, though, are they?

I've *heard* of the Conroe-L which should be a single core Core 2 Based CPU, which should overclock nicely...

Thought they came out a coupla months ago...

I heard they are practically the same as the Core 2 Duo's (Overclocking and performance wise) if you don't count having less cache and only one core.