RAM frequency seems wrong

[Dynesh]

I have absolutely no clue when it comes to RAM. I just set this new system up, as outlined in my sig. The RAM showed the wrong timings in the BIOS, so I set it to 5-5-5-15, but CPU-Z still shows my frequency at 333.9mhz. I think this is supposed to be 400, but I'm not really sure. The only thing I see in the BIOS that seems to go with this would be the DRAM Frequency setting, which is set to Auto. The lowest option is 400MHz. Should I change this, or am I fine, or what. Any ideas?

Here is the link to the RAM

[polobunny]

333 x 2 = 667Mhz

You want to set yours to 800Mhz to run at optimal performance. :)

[screwballl]

lets see, 800MHz memory and 533MHz cpu fsb = 2:3 divider (for stock speed)

more info HERE

[Dynesh]

I set the DRAM frequency setting in my BIOS to ddr2 800, and cpu-z is showing 400MHz , but the FSB:DRAM ratio is showing as 2:3. Should I leave it or do something to get that ratio to 4:3?

[screwballl]

I am sorry 2:3 is correct... I was thinking 400 x 2... I changed my post above. 4:3 is for 400MHz memory, not 800MHz memory

a few things for over clocking, remember to do it in small increments....
set it to 4:5, OC the cpu fsb to 320 which will set the memory speed to 803MHz = 2880MHz cpu speed (400MHz gain)
or since it is OCZ memory, you could step it up to around 853MHz which means cpu fsb of 340 = 3060MHz (600MHz gain)...

remember, small steps.... so start with just changing the divider to 4:5 which actually underclocks the memory to 667MHz, make sure it boots fine. then bump the cpu fsb from 266 to say 276... make sure it boots and maybe run prime95 for 30 minutes.... then 286... then 296 and eventually to the 320 or 340... make sure you have TAT handy there for the temps. If you notice temps reaching the upper 50s under load that will be your limit. Sometimes you may end up with memory at 753 and cpu at 300 giving you 2700MHz or other times you may get a good memory set and cpu that will allow for over 3GHz...

again, very important, small steps

[Panda Man]

Originally Posted by Dynesh

I set the DRAM frequency setting in my BIOS to ddr2 800, and cpu-z is showing 400MHz , but the FSB:DRAM ratio is showing as 2:3. Should I leave it or do something to get that ratio to 4:3?

Your memory is DDR, which mean Double Data Rate. The REAL clock is 400MHz, however the EFFECTIVE clock is 800MHz. CPUz shows the real clock of your memory.

Change the ratio to 4:3, at 2:3 your FSB is only at 533MHz, when it should be at 1066MHz. This will explain why your memory is running at DDR2667 rather than DDR2800.

Guys, note the first thing he said - he is new to this, so be sure to explain things

[Dynesh]

Ok, I'll mess with it in a little while, but I need something cleared up. When you say change to 4:3, is there a setting in the bios that does this, or do I need to look at the chart and change the settings for what 4:3 should be? If that makes sense.

[gvblake22]

Originally Posted by Dynesh

When you say change to 4:3, is there a setting in the bios that does this, or do I need to look at the chart and change the settings for what 4:3 should be? If that makes sense.

All motherboards and BIOS's can list it differently, but it usually appears as a ratio like 4:3 or as a speed like 667 or 800. In your case, you will want to set it to 800

[screwballl]

If you have memory rated at 800Mhz, you use 2:3

2:3 = 800Mhz memory (PC2 6400) with 1066 MHz CPU bus
4:3 = 400Mhz memory (PC2 3200) with 1066 MHz CPU bus

1:1 = 533Mhz memory (PC2 4200) with 1066MHz CPU bus
4:5 = 667MHz memory (PC2 5300) with 1066MHz CPU bus

If you were to set that at 4:3 but keeping the memory at 800Mhz, then you would literally be doubling the CPU speed to 4.8GHz and likely the PC wouldn't boot. But if you set the 4:3 with memory at 400, then your memory would be underclocked by half to 400Mhz instead of 800Mhz (thus rendering it as 200Mhz doubled or same as PC2 3200) and the CPU would stay at the same stock speed of 2.4GHz.

So for small but decent OC, setting it to 4:5 would keep the memory close to its rated speed but OC the CPU to almost 2.9GHz

In the case of my DS3, it uses a "memory multiplier". So stock speed for me using DDR2 667 goes like this:
mem spd = 667 (333.3MHz doubled)
mem multiplier = 2.5 (fsb before quad pump times memory multiplier = memory speed)
so in my case: 266.5MHz cpu fsb times 2.5 = 667 (266.5Mhz quad pumped is 1066MHz fsb)
Official ratio for 667 memory is 4:5 to keep cpu and memory both at stock speeds

in the case of 800Mhz memory, I would use a memory multiplier of 3 on this board:
266.5 x 3 = 799.5

[Panda Man]

I stand corrected. For some reason I was thinking FSB:DRAM :0