CPU talk/server upgrade

[Elvicat]

Ok so i'm trying to figure out what i should do in this matter, i have 3 computers running 24/7 and i'd like to push together 2 of them to save power, the problem is they are rather old pc's.

1 is the webserver running yeah you know webserv stuff and a torrent server, the pc runs centos 5.x and cpu is just a pentium 3 @ 600mhz, 512mb ecc ram but funny enough it does what it should do with ease.

The other is the minecraft server, a pentium 4 hyperthreading cpu at 2.8GHz and running centos 6.x, 2.5Gb ram.

I'd like to maybe find a dual core system that's equal or beter in strengh, this would normaly be easy but there is that minecraft ONLY uses 1 CORE not any more.
So what i'm asking is, how much GHz do i need on a dual core to make these 2 pc's into 1, is it 2.8GHz or more or under, this has confused me for a while and not many seem to know, i have the feeling say a 1.8GHz dual core would get whooped by this 2.8 single with ease.

Please help.

[bilbous]

start logging your hardware resources and see how much processor/ram usage actually is. It could well be that the minecraft server is all you really need. Do you get a lot of web traffic? if not then that server will not use a lot of resources. Does the minecraft server tax its machine under heaviest load?

If you get a multi-core box it may be possible to dedicate one core to minecraft and any others to the webserver.

[Elvicat]

I'm too much of a linux noob to even know where to start with that and i'm usualy loged out of that system when not using it directly so the server app just runs in the background.

I've never really had much taxing on that system and no not much webtraffic on the webserver tho sometimes the torrent server takes a lot of traffic.

Meh i should really find a small sata drive for that system, even if it's fast already for linux any loading from the hd slows it down as it's an ide right now but i noticed it had sata so that may be a small upgrade atleast.

[bilbous]

ya torrents, my eyes glossed over that when I was composing my reply. I'm more of a linux pretender myself, most of what I ever knew is out of date at best.

[LigH]

The most important advantage of multi-core CPUs is that heavy load on one core doesn't stall the whole CPU. This risk only happens for a flood of hardware IRQs, e.g. heavy disk access and memory management. (I know a Windows program which is able to lock my mouse pointer while loading.)

I am no expert for your situation, but I am pretty confident that your suggested hardware will easily manage the tasks you expect.

[Elvicat]

A pentium 4 with hyperthreading acts as a dual core so it doesn't lock up really.

[LigH]

Well, HT has its limits. It depends on parallelizable instructions. But the virtual cores are not really independent. Two physical cores are "safer" regarding multithreading.

[Rigwyn]

What's tricky about that is the concept of threads. A thread can get locked up - halting execution even though you have another processor that's free. There's no guarantee that the two cores will be used optimally or that the load will be balanced evenly.

I once did some performance testing on a Sun T2000 - it sported two of their new Niagara processors - each of which had four cores and four way hyperthreading. This effectively made it act as a 32 way multiprocessor.  I was shocked at the time to see  that it was no faster than my old windows desktop pc when running server side java apps. What I discovered was that most apps were not written to take advantage of the multiple cores. They didn't create additional threads to farm the load across the processors. On top of this, the os's scheduler was lazy - delaying the execution of processes in order to make it look like the processors were barely used.

Two cores or one hyperthreaded core is certainly preferred, but don't expect magic. :-)

[Elvicat]

Rigwyn i'm trying to figure out what i need to run these 2/3 server apps on 1 computer instead of 2 where at the same time there is some overhead so it doesn't lockup.

I doubt i'd go for a completely new computer for just these things that's just too much money to throw away.