I'm facing low RAM performance and weird BIOS restrictions on an abit motherboard. I will outline the details below.
The topic is relevant to RAM timings and latencies, advanced BIOS switches and the like. If you're illiterate in these areas, don't read further.
Important system details:
abit AN-M2 motherboard using the latest BIOS
- nForce 630a chipset
- 4 GiB of DDR2 in a 2+2 configuration in DIMM slots 1 and 2
- onboard FDD and HD audio both switched off, IDE and SATA both enabled, no RAID, SATA ports 2 and 4 occupied, 1 and 3 empty (sometimes swapping around seemed to do differences)
Less important system details
- AMD Athlon64 X2 4000+ overclocked - RAM overclocked too
- nVidia GeForce 8800 GT overclocked
- Creative Audigy ES overclocked (no, kidding
) - don't worry, I don't buy Creative, I got this used for 9 dollars because of the features - hate them or not, those features are golden for this money with Daniel K's drivers and unlockage
I've made another forum post about several Creative cards crackling used with this motherboard - many people online blame nForce chipsets and I seem to believe that now. Crackling and general problematic behaviour was tracked back to RAM itself - so I'm hoping that this thread will allow me to hit two birds with one rake. Specifically, abnormal and/or high RAM usage lead to buffer starvation on Creative cards and this is slightly mitigated when running dual-channel - examples include scrolling in Firefox (worst of all, so I assume the program is systematically raping my RAM) and certain conditions in Crysis, mostly many flame/fire/smoke effects on screen (still much less severe than Firefox).Finally, the issue itself:LOW MEMORY PERFORMANCE.
Why, oh tell me why, does this board perform like a load of crap? Seriously, it's severe. Let me outline it in detail:
1. Throughput is low. By that, I mean F- DAMN SLOW. I've used a much more budget AsRock board before with an nForce 4 chipset and onboard audio only - using overclocked 667 MHz DDR2, memory throughput was knocking at the doors of 8000 MiB/s when reading and exceeded it when copying (latest Everest). THIS BOARD HOWEVER, oh please, this could only reach 6500 MiB/s read times when I packed it with my new 800 MHz DDR2 modules which I overclocked all the same. Overclocked 667 performs faster in a low-end motherboard than overclocked 800 does in a sort of almost-mainstream motherboard. Why? (Also, the AsRock board was stressed with 4 modules of 1 GiB each, while this board only has to hold up 2 - need I say more?)
2. BIOS behaves oddly. No matter what I set for some timing numbers, they stay high. I am able to configure the first 3 but the last 2 are locked at abnormal values - RAM boots up using 5-5-5-18
. Strangely enough, nTune under Windows can physically change them to more normal values once I've finished booting, but that's tedious to do every time. I'd like to know where to kick this piece of poop to make it behave. (Note: I'm considering buying a better brand like Gigabyte next time, or maybe even MSI, and contemplating opting for AMD's 7 series of chipsets.)
3. There are BIOS values that I know nothing about. For now, I'd like to know about latency. Here goes:
The BIOS set DIMM latencies to these values (or something like it - typing from memory): DIMM1: 127.5 ns -- DIMM2: 75 ns -- DIMM3: 75 ns -- DIMM4: 75 ns
I found this odd, but google revealed it's not an isolated case.
Experimentation: setting all the latencies to 75 ns creates an unbootable, unrecoverable system that will not POST and allow the recovery keyhold ("Insert" key for this board) to make it POST, meaning I need to flush the CMOS.
Setting both latencies to 127.5 ns does work, however, but I feel no differences yet. What is the purpose? Is it better to keep modules in sync? I would guess: yes. But I honestly don't know what this does. Note: between the two values mentioned, I can set 105 ns as well, but I have yet to try whether it will POST.There are a number of points above which need advice/answers, and I would appreciate all the help I'd get.