XEON Processors

vbimport

#1

My PC has got two Intel XEON 2.4GHz processors in (not one dual-core, two physical processors) and I’m not sure if it’s actually using the power of both, or running on one, etc. Is there any way to find out / change it so that both are being fully utilised? Thanks,
/Arcarax


#2

The only way to use both is to use applications that are multi-threaded and that are multi-cpu aware.

The majority of applications out there still don’t recognize more than a single core. In time that will change as dual-core is the future… Alas the change is occuring at a very slow pace.


#3

Ok, thankyou for the information, really appreciate it
/Arcarax


#4

Apparently, there is a fairly simple test to see if Windows is running on two processors or with hyper-threading: Bring up the Windows Task Manager (Shift + Ctrl + ESC) and go into the ‘Performance’ tab.

Just to cover various single / dual CPU setups with/without hyper-threading, I’ll compare various setups: :wink:

If you have one CPU without hyperthreading such as a Celeron, there will be one CPU usage history graph. You will also get only one graph if you have a hyperthreading capable processor with hyperthreading disabled. Apparently, I have seen Dell PCs shipped with hyperthreading disabled by default, which must be enabled in the BIOS setup.

For a PC with a hyperthreading / dual-core CPU (such as a Pentium 4 HT or AMD X2), there will be two CPU usage history graphs. If you have a look in the ‘Processors’ section in the device manager, it will also appear like you have two CPUs installed (same CPU listed twice). When a single-threaded application is running at full processing power, one of the CPU usage graphs will be maxed with the other showing idle usage. However, if you have a multi-threaded application maxed out (or two single-threaded applications using max processing power), both graphs should max out.

If your PC has two XEON (or other) CPUs that are not hyperthreading capable (or with hyperthreading disabled), there will be two CPU usage history graphs in the task manager also; each showing the CPU usage for the given processor.

Finally, if you have two XEON (or other) CPUs that with hyperthreading enabled (or are dual-core), there will be four CPU usage history graphs in the task manager; two graphs per processor.

A simple way to test if a CPU intensive application is single or multi-threaded is to get it to run at full processing power. For example, if this is an MP3 encoder, give it a couple of songs to encode. If only one CPU usage history graph is maxed out in the Task Manager, then the application is either single-threaded or set to run on a single thread. However, if two or more CPU usage graphs are maxed out, then it is multi-threaded.

Going by your PC set up, you should have 4 CPU usage history graphs in the Task Manager; asssuming the CPUs have hyper-threading capability. :slight_smile:


#5

Thanks for doing that research. Having just checked, I do have 4 graphs in the CPU Usage History section, and normally one is working a little while the others seem to be idle. Really appreciate knowing this. Does this mean I have two XEONs with HyperThreading or Dual Core? Thanks again,
/Arcarax


#6

If you are familiar with the command-line MP3 encoder LAME, this would be a good way of determining if the CPUs are hyper-threading or dual-core and if they are running properly. First use it to encode a given song and note down the speed it ran at when it completes (LAME is a single-threaded application). Next, run two instances of LAME (one per command-line Window); each on a separate copy of the same song (attempt to start them at the same time or use a batch file) and note down the speed both ran at. If both CPUs are running correctly, you should get roughly the same encoding speed in the first test as for each encoding in the second test. Finally, attempt to run 4 instances of LAME; each on a seperate copy of the same song. If the encoding time of each is lower than the previous attempt (such as more than 10%), then the CPUs are hyper-threading, otherwise if you get roughly the same encoding speeds as with running two instances of LAME, then they are more than likely dual-core. From my last experience with a Dual XEON hyper-threading capalbe CPU PC (can’t remember the speed or LAME version), I got 10x encoding for one and two simultaneous encodings and 8x for four simultaneous encodings (from what I recall). :wink:

There are various system diagnostic tools that can show the number of CPUs, whether they are hyper-threading and possibly if they are multi-core capable. One worth trying is SIW, which is freely available.


#7

I’ve never tried LAME, but I’ll search it out and give it a try, and post the results (if I remember - college is demanding :))

I’m downloading SIW as we speak, and will aim to try that out this evening. Thanks again for all the help I really appreciate it :slight_smile:
/Arcarax