The NEW Build Your Own Arcade Controls
Main => Main Forum => Topic started by: DeLuSioNal29 on February 17, 2010, 04:04:55 pm
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Hello all,
I recently upgraded my arcade PC from single channel DDR2 800 to DDR2 1066. (RAM was a hand me down from my normal PC which I upgraded to Dual Channel RAM). When setting it up in BIOS, I had the option to enable/disable Unganged mode.
My question is... Which is faster for MAME? Ganged or Unganged mode? I read somewhere that ganged is better for single core performance and unganged is better for multi-cpu applications. Any thoughts?
Thanks!
DeLuSioNaL29
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Your processor (I'm guessing a Phenom) has two memory controllers on the CPU. Ganged is setting both memory controllers to work together which allows data (that is being used by all cores) to await on the queue until they are accessed. Unganging means that the two controllers work independently. This allows them to work asynchronously with reference to individual clocks with their one or two Dimms.
For example, if you have DDR2 800 memory and you leave your bus speed at the default 200mhz and run in ganged mode you will have your memory running at its intended 800mhz. But if you overclock the bus speed to, say, 220mhz, and leave your memory ganged then your memory will now be running at 880mhz which likely will make it less stable and open your system up to crashes. But if you have your memory unganged you can lower the memory multiplier from 4 to, say, 3.33 and your memory will now be running at 666mhz, which is slower than its intended speed but more stable.
Anyway, this should give you a good idea. Basically, if you're not overclocking your PC and you're leaving your bus speed at its default then keep it at ganged. The main exception to this is if you have a quad-core, in which case unganged will typically give you better memory performance. If you're overclocking you'll most likely want unganged since you may want to overclock your bus, and thus your processor, without overclocking your RAM.
As for MAME performance, I'll doubt you'll see a substantial difference in speed between the two since MAME really is tied to raw clock speed more than anything else.
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Hello all,
I recently upgraded my arcade PC from single channel DDR2 800 to DDR2 1066. (RAM was a hand me down from my normal PC which I upgraded to Dual Channel RAM). When setting it up in BIOS, I had the option to enable/disable Unganged mode.
My question is... Which is faster for MAME? Ganged or Unganged mode? I read somewhere that ganged is better for single core performance and unganged is better for multi-cpu applications. Any thoughts?
Thanks!
DeLuSioNaL29
Benchmark your machine each way, see if it makes a difference, and post the results imo
:cheers:
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I don't have a Phenom. It's a dual core Athlon X2 chip. http://www.newegg.com/Product/Product.aspx?Item=N82E16819103678 (http://www.newegg.com/Product/Product.aspx?Item=N82E16819103678)
Does it make any difference?
P.S. - I read you can "unlock" the quad processors with this particular dual core CPU. Is this true?
D
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I don't have a Phenom. It's a dual core Athlon X2 chip. http://www.newegg.com/Product/Product.aspx?Item=N82E16819103678 (http://www.newegg.com/Product/Product.aspx?Item=N82E16819103678)
Does it make any difference?
P.S. - I read you can "unlock" the quad processors with this particular dual core CPU. Is this true?
D
I wouldn't waste my time trying it. When a processor comes off the line, it's tested. If one or more of the cores fails to perform up to standards, mainly heat and correct output, the core is considered useless. It's commonplace to take some of these useless processors, and if X of them are still usable, disable the failed cores, and release it as a lower grade processor.
So basically, there may be 4 cores there, but at least one of them has major heat problems or produces incorrect output, possibly both of them. It'd be more of a headache to enable them.
This whole thing is not uncommon. Nvidia and ATI use partially failed GPU's as lower grade offerings. It's probably not well know, but the Cell processors in the PS3's are often not fully functional either. IIRC, there can be as many as two failed subprocessors on a Cell and Sony will still use it for PS3. IBM sells Cells with even more failed subprocessors for use in consumer products like Blue-ray players.