System memory VS per iteration time
 

I recently upgraded my 2500 to 16GB from 8GB and noticed that the per iteration time for 45M exponents has dropped from .033 to .023. In addition, running mfaktc on the 560 on it used to hit around 160M/s while P95 was running and 180M/s if nothing was running, but now I notice that a single core is running at 209M/s while P95 runs, and gets up to 230M/s if I have nothing running. I knew that the increase in memory would impact the P-1 time, but the change in LL and mfaktc were kind of startling. Anyone else notice changes when they upgraded memory?

Things to check:[LIST][*]If you were running in double channel mode with your memory before, are you still doing so now? If not, your memory bandwidth just halved.[*]Has the frequency of your memory lowered? If so this could be because you got slower RAM, or simply that your motherboard defaults to lower settings when more RAM slots are populated, this second issue could be fixed in the BIOS.[*]Do all of your RAM channels have the same amount of memory in?[*]Other things I have forgotten.[/LIST]I recommend grabbing CPUZ:
[url]http://www.cpuid.com/downloads/cpu-z/1.59-setup-en.exe[/url]

It's free and will give you lots of information about your system, including info on every RAM module. The Memory and SPD tabs will be especially helpful here. You can check out the memory in all of your RAM slots individually on the SPD tab.

If you happen to know the exact make and model of RAM modules in your system that would help, but even general information or that gleaned from CPUZ will help. Any information you have about the rest of your system would also help here.

Edit: Since you mentioned a 2500, I would think the most likely culprit is that the RAM you bought only runs at the advertised speeds at 1.65 V, but the processor requires that the RAM be run at 1.5 V, therefore your memory system has to run slower and there is a corresponding drop in memory bandwidth.

[QUOTE=lavalamp;283529]Things to check:[LIST][*]If you were running in double channel mode with your memory before, are you still doing so now? If not, your memory bandwidth just halved.[*]Has the frequency of your memory lowered? If so this could be because you got slower RAM, or simply that your motherboard defaults to lower settings when more RAM slots are populated, this second issue could be fixed in the BIOS.[*]Do all of your RAM channels have the same amount of memory in?[*]Other things I have forgotten.[/LIST][/QUOTE]

His computer became _faster_ after addition of memory :smile:

My guess is, with the second dimm populated, things are now operating in dual channel mode. /SWAG

[QUOTE=axn;283530]His computer became _faster_ after addition of memory :smile:

My guess is, with the second dimm populated, things are now operating in dual channel mode. /SWAG[/QUOTE]

Dual channel mode... soemthing else new I have to research lol.

And axn is correct, my computer became much faster with the added RAM, not slower. All of the RAM is Corsair Vengence 1600MHz, I know better than to mix and match memory, especially on a home built system.

bcp19, the simple example of "dual channel" mode is that there are two system memory busses...each independent, each offering the same number of memory transactions per second. Mfaktc and P95 both max them out, so, less overhead, become faster if multiple channels are operated in parallel.

P.S. The memory is TEMPTING!!!!

[QUOTE=axn;283530]His computer became _faster_ after addition of memory :smile:

My guess is, with the second dimm populated, things are now operating in dual channel mode. /SWAG[/QUOTE]Ah, somewhat misread that then. In that case roughly the opposite of what I said applies.

[QUOTE=Christenson;283613]bcp19, the simple example of "dual channel" mode is that there are two system memory busses...each independent, each offering the same number of memory transactions per second. Mfaktc and P95 both max them out, so, less overhead, become faster if multiple channels are operated in parallel.

P.S. The memory is TEMPTING!!!![/QUOTE]

So, since my MB has 4 slots, one channel is for the first 2 and the second channel is for the secod 2? All I did was add 2 more banks of memory to the open slots.

I just downloaded CPU-Z and it tells me that I am running at 4.3GHz... I had not played around with the overclocking on the MB yet, so it appears there is some sort of auto function going on, which could be behind the speed increase. I have an ASUS P8P67 Deluxe, anyone know if this could be true?

[QUOTE=bcp19;283662]So, since my MB has 4 slots, one channel is for the first 2 and the second channel is for the secod 2? All I did was add 2 more banks of memory to the open slots.[/QUOTE]

Some boards with multi-channel memory alternate slots (1-2-1-2), and others group them (1-1-2-2).

The two mobos I've had are of the second sort, so with only two sticks in four slots you'd need to alternate them to get dual channel operation. Take a look in your mobo manual. Many motherboards do come with auto-overclocking, but even those still usually need to be selected in the BIOS... again, check the manual. Post a screenshot of CPU-Z?
And some specs: [url]http://www.asus.com/Motherboards/Intel_Socket_1155/P8P67_DELUXE/[/url]

[QUOTE=Dubslow;283711]The two mobos I've had are of the second sort, so with only two sticks in four slots you'd need to alternate them to get dual channel operation. Take a look in your mobo manual. Many motherboards do come with auto-overclocking, but even those still usually need to be selected in the BIOS... again, check the manual. Post a screenshot of CPU-Z?
And some specs: [URL]http://www.asus.com/Motherboards/Intel_Socket_1155/P8P67_DELUXE/[/URL][/QUOTE]

Here's a screenshot of CPU-z. The only thing I remember doing in the BIOS was to set the boot order and there were three options, green, balanced and performance, of which I selected balanced. (and this is on a stock Intel heatsink, I have an H60 in the mail)

[QUOTE=bcp19;283797]Here's a screenshot of CPU-z...........[/QUOTE]

Just out of curiosity, what does the Memory tab in CPUz show?

That speed is pretty impressive for the stock cooler.