General questions about Dual processors

Computer Forum CPU, Motherboards and Memory
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I have a few questions regarding dual processor motherboard rigs.

Q1. You aren’t forced to use 2 processors are you? You can use one processor and leave the other slot/socket empty.

Q2. I believe you can’t use two Celerons? They must be Pentiums?

Q3. Do the two CPU’s have to be matched in speed and FSB. Can i install one 700MHz and one 800Mhz for example?

Q4. Which Operating Systems support dual processors? I believe Windows NT4.0, Windows 2000 Pro, Windows XP Professional and Server 2003 do?

Q5. Does software have to be written to specifically make use of dual processors, or does the OS handle that automatically? What I mean is will i actually notice more power, or only with specific software, ie server software.

Q6. Lets say I open MS Word and MS Excel at the same time. Will the job of loading Word be sent to one processor and Excel the other? Or do they share the same workload?

That’ll be all for now :wink:

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  1. Most boards allow you to use 1 OR 2 CPU’s. You’re not forced to use 2.

That’s all I know for sure, I’m a bit iffy on the other ones sorry :frowning:

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  1. Only some CPUs are guarunteed to work in multiple CPU motherboards, e.g. Athlon MP is a SMP version of the Athlon XP designed for dual processor systems.

  2. As far as I know, the CPUs must have the same FSB speed otherwise they could not exist on the same motherboard. Might be wrong though.

  3. Parallel processing doesn’t work as simple as that I’m afraid. Windows won’t necessarily distribute the CPU time among both programs symmetrically although it does help in some situations where you’re running a virus scan while playing a game etc.

  4. Windows 2000 and XP support dual CPUs, but not more I believe. Some versions of Server support more.

  5. This is quite a common topic. The simple answer is no the OS won’t necessarily balance the CPU time evenly among the CPUs. A lot of the time if the software itself (or some of the newer games) isn’t already optimized for TLP then you’ll have 1 CPU doing everything most of the time.

Dual processors can be emulated very well and cheaply by AMD’s Athlon 64 X2 CPUs, which are very good and offer 2 true processing cores.

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I’d suggest going dual-core, it’s cheaper by far. You’ll get similar performance for the most part yet lower power requirments, less heat, no specialty mobo needed, and just one processor to worry about if things go awry.

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[QUOTE=jonbenge]
I have a few questions regarding dual processor motherboard rigs.

Q1. You aren’t forced to use 2 processors are you? You can use one processor and leave the other slot/socket empty.
[/quote]

Yes. Some motherboards, particularly with the Slot 1 or 2 boards, required a terminator card in the empty slot, but that was included if it was required.

Q2. I believe you can’t use two Celerons? They must be Pentiums?

For the most part. The Celeron’s up to 533MHz were SMP capable. The 533A Celeron was a new core that Intel removed (or disabled) the SMP capabilities from. Abit’s BP6 was one of a few SMP motherboards that could natively run Celeron’s in SMP, and probably the main reason why Intel nixed Celeron SMP.

Q3. Do the two CPU’s have to be matched in speed and FSB. Can i install one 700MHz and one 800Mhz for example?

Yes. As long as they have the same FSB and multiplier, you’re okay. While a few people have been able to run two separate speed CPU’s at their varied speeds, there tended to be a lot of stability issues, so even if you were successful in making the thing work, good luck finding an OS that won’t barf on you.

Q4. Which Operating Systems support dual processors? I believe Windows NT4.0, Windows 2000 Pro, Windows XP Professional and Server 2003 do?

.
Yup. NT4, all Win2k varieties, XP Pro, and Server (any server version of an NT-based Windows OS will support dual- or more processors).
Also, most Unix-based OS’s will (*BSD, Linux).

Q5. Does software have to be written to specifically make use of dual processors, or does the OS handle that automatically? What I mean is will i actually notice more power, or only with specific software, ie server software.

If the software is written to take advantage of 2 or more processors, then, yes, it will automatically do so if the need arises. Otherwise, the OS will do load-balancing to divvy up the work. So you could run some video encoding and play some Doom 3 while you wait, and not suffer performance (assuming you’ve got a decent setup—not a pair of Celeron 500’s and a GeForce 2MX).

Q6. Lets say I open MS Word and MS Excel at the same time. Will the job of loading Word be sent to one processor and Excel the other? Or do they share the same workload?

Typically, the first processor will be loaded up, but this depends on the size of the load and the OS.

Since you’re looking and dual processors, you might want to hit up 2CPU and read up some of their articles and stickies in their forums.