CVData and CVCX have a Threads option which specifies the number of threads to be used in running a sim. Multiple threads means that you can run multiple hands at the same time, greatly increasing the speed of the simulation. Assuming that the processor can handle it, four threads will run nearly four times as many hands a minute. Multi-threads are supported by the following simulators: Standard, Multi-tracking, Real Shuffle, and CVCX. It is ignored for index generation. Problem is, how do you know the number of threads to specify.

The first step is to determine the processor model. You can look this up on Google. Examples of processor models are i5-430M and i7-4790. Now you can look up the processor. Google Intel i5-430M or Intel i7-4790 for these two examples. This should bring you to the Intel specs for that processor. Now, look for # of Cores and # of Threads. If they are equal, there is no Hyperthreading. If unequal, there is Hyperthreading. The two cases are discussed separately below.

No Hyperthreading

When # of cores and # of threads are equal, there is no Hyperthreading. That is, all threads are fully independent. You can set the CV threads option equal to the number of cores for maximum speed.

Hyperthreading

If there are more threads than cores, the processor has Hyperthreading. Setting threads depends on the chip architecture. Generally, chips manufactured in the last four years allow a higher thread setting. Suppose the chip has four cores and eight threads. With older chips, five threads will work well. With newer chips, six or seven is possible. Even eight is possible, although the additional gain will be less. If you’re using higher numbers, make sure you have cleaned the dust out of the heat-sink, fans and filters and the room cannot be hot. Intel chips cannot be damaged by too much heat. But, they will shut down, forcing a reboot. I have increased the voltage to my Intel i7 chip by 20%, greatly increasing the heat generated, and regularly run seven threads.

Notes


  • Instead of using 100% of the processor, CV will turn control over to the Windows scheduler thousands of times a second and pause every few milliseconds to keep from locking up the machine. This slows the sim by about 5%, but allows the PC to continue to perform smoothly. So, even if you use all the cores, you will still be able to run a browser or other apps. If you wish to run other applications that require significant CPU time, you can set Run low priority and CV will instruct Windows to only give it processor time if no other task wants it. If the machine is sluggish, you can reduce the threads. For example, with a two core processor, you can set threads to 1.5. There really isn’t such a thing as a half a thread. What CV does is run two threads, but only allow each to use 75% of a core.
  • If you are using a laptop, you may run into overheating problems, although the M chips are lower voltage and create less heat. I would avoid putting the laptop on your lap if you want to conceive children.