What is SMP? - Short for Symmetric Multi Processing, refers to a computer with two or more CPUs, which allows for the CPU load to be equally distributed between the CPUs.
What type of CPUs do I need to for a multiprocessor system? -
AMD CPUs:
- AMD Opteron (200 series Opterons are designed for single or dual CPU configuration, 800 series Opterons are designed for 4-8 way CPU configuration)
AMD Athlon MP (only AMD CPU designed to operate in SMP using the AMD 760MP/760MPX Chipsets)
AMD Athlon XP (modification may be needed - not supported by AMD)
AMD Duron (modification may be needed - not supported by AMD - Morgan Core Durons are only compatible with AMD 760MPX Chipset - Spitfire Core Durons are only compatible with AMD 760MP Chipset)
AMD Athlon (Thunderbird Core - not supported by AMD - only compatible in SMP with the AMD 760MP Chipset)
For more information on modifying your AMD CPUs to work in SMP, see the AMD 760MP/MPX FAQ.
Intel CPUs:
- Pentium Pro
Pentium II
Pentium III
Xeon (II, III, & IV)
Celeron I (not supported by Intel - only pre-533a Celerons are SMP enabled)
Can I use an Opteron 100 Series CPU in SMP? - No, Opteron 100 Series CPUs are to be used in single CPU configurations only. AMD Opteron model number chart.
Can CPUs of mixed speed function in SMP? - Yes, however, I suggest against it. When CPUs of mixed speed are used in SMP, system stability is compromised.
Do both CPUs have to be the same stepping in order to function in SMP? - No. You can mix CPU steppings in SMP.
What operating systems support SMP? -
Microsoft Operating Systems:
- Windows XP Professional (supports two CPUs)
Windows 2000 Professional (supports two CPUs)
Windows 2000 Server (supports four CPUs)
Windows 2000 Advanced Server (supports eight CPUs)
Windows 2000 Data Center (supports thirty-two CPUs)
Windows NT 3.1 - 4.0 Workstation (supports two CPUs)
Windows NT 3.1 - 4.0 Server (supports four CPUs)
Windows NT 4.0 Server Enterprise Edition (supports eight CPUs)
Windows Server 2003 Web Edition (supports two CPUs)
Windows Server 2003 Standard Edition (supports two CPUs)
Windows Server 2003 Enterprise Edition (supports four - eight CPUs)
Windows Server 2003 Datacenter Edition (supports eight - thirty-two CPUs)
Non-Microsoft Operating Systems:
- Linux (supports 2+ CPUs)
Unix (supports 2+ CPUs)
BSD (supports four CPUs)
Solaris 8.0 (supports 128 CPUs)
BeOS 5.0 (supports eight CPUs)
OS/2 Warp 4.0 (supports sixty-four CPUs)
Does Windows 95/98/98SE/ME support SMP? - No, these operating systems do not support SMP. Though you can use multiple CPUs under these operating systems, only one CPU will be detected and used, while the other(s) will sit idle.
Does Windows XP Home support SMP? - No, Windows XP Home does not support SMP. Though you can use multiple CPUs under Windows XP Home, only one CPU will be detected and used, while the other(s) will sit idle. Windows XP Home does however support Hyperthreading.
Where can I find out more information on Hyperthreading? - Here are a few links that I have found very helpful:
- [url=http://www.tech-report.com/reviews/2002q4/pentium4-3.06/index.x?pg=1]Intel's Pentium 4 3.06GHz processor with Hyper-Threading
Two heads and a whole lotta hertz[/url]
Introduction to Multithreading, Superthreading and Hyperthreading
Team Xeon FAQ
Will every program running under a SMP aware operating system use both (or all) my CPUs? - Not quite, for a program to use multiple CPUs, it must be multithreaded.
What is multithreading? - First, you must understand the basic concept that programs break up tasks they need to accomplish into threads. Unfortunately, most programs we use are single threaded, which means the program executes tasks in a linear order, and uses only one CPU. A multithreaded program is designed to execute tasks in a parallel manner over multiple CPUs. This allows the program to take advantage of multiple CPUs, and balance the load equally between the CPUs.
What programs that I run are multithreaded? - This list is quite comprehensive, and contains many multithreaded applications/programs that you may be using.
What games that I run are multithreaded? - This list contains a good number of the games that are capable of SMP.
What kind of performance increases will I see in a SMP environment? - I should clear something up here, you will not see 100% performance gain very often in a SMP environment, you will likely never see it. As long as you are using a SMP-Aware Operating System, the operating system will then distribute the load equally between processors. This breathes new life into the term multitasking. If you have ever had a program crash, freeze, or BSOD on you while doing heavy multitasking, it could have been that your CPU that was bogged down at 100% CPU utilization. This is not the case in SMP. Because of this load balancing, reliability & stability are tremendously increased. SMP computers are designed to handle these heavy loads, and do it very gracefully. In general, SMP computers are more stable. This is because they are designed for high priority work environments.
Also see 2cpu.com for more information regarding SMP.
If you have any comments, suggestions, updates, or see any errors, PM me.
