SPD Detection (975x Mobo/Ram Problem)

[kentuckyser]

Hello, I just built a new rig with these parts:

Mobo: http://www.newegg.com/Product/Product.asp?Item=N82E16813121059
RAM: http://www.newegg.com/Product/Product.asp?Item=N82E16820231065 - 4 GB
CPU: E6600
CPU Cooler: Thermalright Ultra-120 w/Scythe 120mm fan
GPU: EVGA 8800GTX Superclocked

I built the system with 4 GB of RAM, installed Windows XP Pro/SP2 and installed the drivers. Computer was running beautiful. I re-started it numerous times due to installing all of my software and drivers...it was very stable. I noticed in the BIOS that the memory was only running at 667 mhz...I suppose due to it not having SPD? The memory recommends 2.0-2.1v, while the motherboard needs memory from 1.8-1.9v....so I guess that's why it's running at 667 mhz instead of 800 mhz? Well, regardless of that.....now I have a problem.

I wanted to try a slight overclock, nothing spectacular....so I raised the FSB from 266 to 300 for a 2.70ghz clock. After saving the settings, the PC wouldn't boot....just a black screen. I tried resetting the CMOS, removing the jumper, everything I could think of but it still wouldn't boot into the BIOS....just gave me a black screen. Then, I tried taking all but 1 GB of RAM out, and it worked. Updated the BIOS, reset to factory settings, but when I try to put all 4 GB of RAM back in, it won't boot or go into the BIOS.

Do I need to get new RAM? Or can I just up the voltage to the RAM to make it run at 800 mhz?

[minsonngo]

Nope... the processor FSB is bottlenecking the DDR2-800 memory you have. That is normal though... for the E6600 processor... the memory should run at DDR2-667.

The only way the memory will run at the DDR2-800 speed is if you overclock.


You can read more about it here: http://www.directron.com/fsbguide.html

[kentuckyser]

So that memory should be fine with that motherboard? Under performance memory settings, it says on "Automatic" settings, the RAM is running at 5-5-5-12 at 667 mhz at 1.86 volts. If I change it to "Manual", I can set it to 4-4-4-12, 800 mhz, and 2.12 volts which is what the memory is rated at. Should I do that?

[Mr.Ferrari]

If you really want. With intel systems you do get small performance boosts from the memory running faster then the processor, that combined with the tighter timings. Although you always take a risk when doing any kind of overclocking. This is a pretty safe move though.

[kentuckyser]

Ok, I just manually changed the memory to 800 mhz, 4-4-4-12 timings, and 2.12 volts. I opened up CPU-Z and it's saying the memory frequency is 400 MHz, 2:3 FSB:DRAM.

Also, under CPU, it's saying my E6600 core speed is 1600.00 MHz with a 6.0 multiplier with a Bus Speed of 266.7 MHz and a rated FSB at 1066.7 MHz. But, under the BIOS it says that the multiplier is locked at 9 and the FSB is 266.

[Mr.Ferrari]

Thats just speedstep turning down the multiplier and clock speed when the processor is not under use. Its to save power and help the processor run cooler.

Everything else checks out fine.

[kentuckyser]

I just tried putting in all the RAM again and it booted up fine with all 4 GB....

I'm going to try raising the FSB up a little bit without touching any voltages and see what happens.

[kentuckyser]

So far I'm up to 2.70 GHz, will let it sit at this speed for a few weeks to make sure it's ok.

[minsonngo]

Just watch the system temps. And if the system starts becoming unstable during use... you need to bring it down a notch.