This has been bugging me for a while now, and nobody seems to know the answer, so I'm posting it here, in the hope that someone might be able to give me an answer

Is there any difference between one dual core processor and two single core processors? Because DELL were doing buy one get one free on single core ones, and I've always wondered whether I should have gone with a dual core one instead, or if it wasn't worth the extra cost.

Simply, two single core processors would require two seperate motherboards, 2 seperate cooling systems, and probably 2 seperate power sources/cases. Essentially, you would have to have twice the hardware to use them, and you'd have to have some idea how to link them together. A single dual core processor would only need one motherboard, one cooling system, one power source, and one case. A deal on 2 processors would only make sense if you intended to either build two (or more) duplicate systems, or were interested in setting up some servers. For most home use, it really isn't practical, and you'd probably never be able to use both processors witin the same task without alot of tweaking.

What? But I only have one motherboard, yet both Windows, Linux, and DELL's special diagnostics software all say I have two... is it because It's hyperthreading, does that make it look like two, when it's only really one?

Strange... I think I should open it up and have a look, see what it is...

EDIT: I just looked in KInfoCenter, and while the processors have two separate IDs, their physical ID appears to be the same. This leads me to believe that there's only one, but I guess I'm going to have to have a look to be sure.

If you already have such a system, open up your computer, you should see two seperate processors (well their heatsinks atleast). Just don't confuse one for the motherboard heatsink (or the one from a videocard). Heatsinks for processors all have fairly large fans above them if your computer is less than 5 or 6 years old.

Well, I opened 'er up, and had a look... there is a processor, but it has absolutely no cooling at all, strangely. Somewhere else on the motherboard, however, was a big heatsink, I couldn't see what was underneath (it was pretty massive). I should mention that none of the hardware in my computer has a fan- instead, there's one massive one (taking up about a quarter of the space), which seems to cool all of them... its quite a strange PC, really.

I'm not quite sure what to make of it... is there anything else on the motherboard which would need a big heatsink? (and probably a fan in most normal computers)

Would it be possible for you to take a picture of the inside and post it so we can see for ourselves what your talking about?

Typically the motherboard itself and any videocards would also require a heatsink. Although in some systems ram can also have a heatsink (if you're overclocking mostly). I wouldn't try to remove any of the heatsinks to see what's below, they're meant to stay put, and trying to move or remove them can usually cause them to stop working.
I'm with IamBatosai on this one, a picture would be really helpful.It would also probably help to know the background of this computer, did someone build it for you (a non-corporate entiry), or did it come factory direct from Dell like that? It might also be good to see a link or something to the computer you bought, or some of the hardware you know of.

Well, my computer is a DELL Dimension 9150, or so it says on the case. Looking around the DELL website, I did find this page, which has a diagram of my motherboard. Unfortunately, neither the heatsink or what looked like a processor are labeled, and what it has labeled as the processor is hidden behind the big fan, so I didn't see it when I looked. I've also found what appear to be the specs for it, here, but as I only got what seems to be two processors on a special offer, it isn't necessarily a huge amount of help.

The graphics card is an ATI Radeon x600, PCI-Express, which does have a heatsink, just no fan. My RAM (1Gb) doesn't have either. I can't tell you who made the motherboard, as it's specially made for DELL, not a commercially available model. I got the computer direct from DELL a couple of years ago, they're the ones who built it. I'll see if I can get a picture for you.

Alright, before you do anything... Can you explain again what you are wanting to do here? Are you trying to get a new processor, or are you trying to figure out what the computer you have can currently support?

If you're wanting to upgrade your processor, I'll save you some time... You can't. There aren't any processors that fit a socket T, (which is what kind of pin sequence and mounting your mother board uses) atleast not on newegg. Since processors aren't something you want to buy second hand, you may just have to deal with what you have. Otherwise you would have to pretty much build a new computer (atleast new motherboard and processor) that fits as works with as much of your current hardware as you can. Which suffice to say, can be a real pain in the ass (especially if you're trying to work an AGP slot, 2 x seta 2 slots, and more than 2gb ram. (I had to settle for 2gb ram myself)) and can cost probably more than you're willing to spend if you don't know how to put the computer together (mistakes cost more than paying someone).

I think he just wants to know whether there's a difference between two single core processors or one dual-core.

And I thought Socket-T was another name for LGA-775 sockets?

Basically, I was under the impression that my computer had two single-core processors, as DELL were doing a buy one get one free offer. I was just wondering if there was any difference in performance between two single-core CPUs and one dual-core CPU. I wasn't planning to upgrade, at least not yet, but thanks for the warning.

Well, unless someone is aware of something I'm not. The essential difference is what I said in the first post. You can't fit two single core processors on the same motherboard. You would need two seperate motherboards, and would need to take additional steps to get them to talk to eachother. A dual core processor can be used in a single motherboard. As I suggested, a buy 1 get 1 free deal would really only work if you were planning on setting up some servers, or were looking to build two duplicate computers.

Going from what you provided, your motherboard only has room for one processor. And if you wanted to still be using the same motherboard, any upgrades would have to fit the same socket. http://en.wikipedia.org/wiki/Socket_T (I stand corrected). The socket seems to support dual core processors, but I can't really tell what yours is. If your processor is only .8 to 1.0 ghz, it's likely a single core, or atleast only has 1 core working. If it's a running at around 2 ghz, you probably have a dual core. I don't think they even bothered to make dual core processors for speeds under 1.4 ghz.
I'm not an expert on hardware, so maybe Iambatosai can provide more answers.

2 Processors on one motherboard is quite possible. They even have 4 processor motherboards. (Example) However, these were made for servers and as far as I know they are only compatible with windows server edition. Or another server OS. I may be wrong though.

Theory:

I'm not 100% sure if this is correct but I'll say it anyway. A dual-core system has one set of RAM. While multi-processor systems have sets of RAM for each processor. So effectively, a dual-core is two processors in one, feeding off of only one set of RAM. While on a multi-processor system (for example 2 processors) each one has it's own set of RAM. Thus each one can have large amounts of RAM, while the dual-core has to share with both cores. More RAM equals faster data transfer. However, dual-cores processors have better architecture. This means more efficient data transfer.

So, in conclusion, I'd say they are about the same. However, a dual-core takes up less space and less power.


Perhaps Vargrant0 or Marxist Bastard could come prove or disprove my theory.

P.S. I must say, (in all modesty) not bad for a 14 year old teenager huh?

Well, if that is the case, and I don't have two processors, then it looks like I have been badly mislead by someone- either DELL, or my mum, who was the one who ordered the computer. Oh well... at least it's hyperthreading, which is almost like dual core. It has 'Enhanced Speedstep technology' too, whatever that means.

Hey, that just gave me an idea! I have an old computer lying around somewhere which is so old it's not really worth using anymore, maybe I could use it to set up a render farm... I know how to do it in Linux, but I'll have to do a bit of research to see if it's worth doing in Windows (there's no point if I'm only going to be using Linux, as I don't play games on it). Should be fun, even if it's not possible

And yes, that was pretty impressive Batosai, maybe some time in the distant future, when everyone makes games for Linux (which would count as a server OS), I might get one of those multi-processor motherboards