Asus P5B Premium - Bios Memory settings Help req.

[Jayos]

I have an Asus P5B Premium mobo

Can somebody please explain the following bios settings and what they should be.

I have changed the timings to match my memory to 4-4-4-12 but not sure what the other settings are and if performance can be improved by tweaking.

CAS# Latency - 4
RAS# to CAS# - 4
RAS# Precharge - 4
RAS# Activate to Precharge - 12
DRAM Write Recovery Time - 4
DRAM TRFC - 42
DRAM TRRD - 10
RANK Write to Read Delay - 10
READ to Precharge Delay - 10
WRITE to Precharge Delay - 11
STATIC Read Control - Auto

[Yellowbeard]

CAS# Latency - 4
RAS# to CAS# - 4
RAS# Precharge - 4
RAS# Activate to Precharge - 12

Tweaking the timings other than the 4 above can offer some improvement. However, the official Corsair recommendation is to manually set to the timings listed above and set 2.1v for RAM voltage. The other timings need to be left at MOBO defaults.

[Jayos]

When my PC boots it states the RAM is 4300 where infact it is 5400

Any ideas?

[Yellowbeard]

What is telling you PC4300? Are you using a utility like CPU-Z or what?

[Jayos]

On the post screen when the pc first boots

[Yellowbeard]

Download CPU-Z and use it. Tell me what info you see under the MEMORY tab and the SPD tab.

[Jayos]

Here ya go - The timing tables do not look right for this memory is this a fault with the memory modules?

1 - Memory

2 - SPD Slot 1

3 - SPD Slot 2

4 - SPD Slot 3

5 - SPD Slot 4

[Yellowbeard]

Your system is underclocking the memory. Do you have an 800mhz CPU?

[Jayos]

Yep P4 560J 3.6

Currently overclocked to 3.8 with FSB 211MHz

Any way to force the correct clock speed for the ram?

[Yellowbeard]

I don't have that board and a CPU to test with. However, you should see some RAM speed selections in the bios that will allow you to select a divider to upclock the memory ASSUMING this is enabled by the bios with 800mhz CPUs. Look for something similiar to DRAM Frequency and numbers like 533, 667, 800, 1066, etc relating to memory speeds. These represent dividers and will upclock the memory in relation to your CPU speed.

[Jayos]

Ok I know I have these settings but which would be suitable for my ram?

running cpu @ 211MHz Which is effectivly 844MHz

If I select the 800 option will this then force the memory to run at 800MHz?
or would it run at 844MHz to match the cpu?

[Yellowbeard]

What specific options do you have for the RAM speed.

[DougMcDonald]

Jayos, with the P5B the POST screen is wrong to put it simply.

As Yellowbeard suggests, CPU-z is the best way to see what your ram is running at.

My ram is PC6400 and the post screen says 4300 too, this seems to happen if you set the memory and cpu timing to 1:1

If you have got it at 1:1, then with your FSB at 211 your ram would be running at 422 which is obviously underclocked.

You can change the dividers to things other than 1:1 and if you are following clunks overclocking guide for the P5B you will most like see 4-5 options. Auto, DDR422, and some other numbers.

I believe that originally these will have been set to 4300, 5400, 6400 and maybe 8500 dividers but technically you could choose one up to 566 (or maybe depending on whether or not the ram would take it (cooling etc))