F2-8500CL5D-2GBPK bests timings

[HiSpeed]

Hi,

I'm using the same RAM (F2-8500CL5D-2GBPK) on my Asus P5E and Asus P5B-E.

@1066Mhz (EPP) the SPD shows : 5-5-5-15-4-47-12-4 (CL-tRCD-tRP-tRAS-tRRD-tRFC-tWR-tRTP I guess)

Curiously, in auto mode, the 2 BIOS use other values coming from elsewhere.
I think the BIOS don't care or can't read SPD/EPP.

What I have to do to ensure stability ?
Have I to set manually the timings, and if yes, what values should I use ?

Thanks for your help,

[G.SKILL]

because of JEDEC standard and better compatibility, the SPD value would only support to DDR2 800
to run DDR2 1066, you need to set the timing 5-5-5-15(tCL-tRCD-tRP-tRAS), memory voltage 2.1v and FSB voltage 1.4v manually in BIOS
thanks


G.S

[HiSpeed]

Yes, I agree, but the 4 first timings are not really a problem.
My problem is from the other ones, my P5E set them to 4-56-13-4 and my P5B-E to 3-42-6-5 in auto...
Further more 42 and 6 are the max possible on my P5B-E...

[G.SKILL]

different motherboard would have different sub-timing
even you set them the same, but they would not perform the same
so, we'd recommend user to keep those sub-timing to motherboard default value
thanks


G.S

[HiSpeed]

OK, but sub-timing is an ambiguous notion because my Asus P5E has 2 sets of timings:
5-5-5-15-4-56-13-4 which is the first set by default, and
8-4-5-4-6-4-6 which is the second by default.

Currently, I've only set manually the first to 5-5-5-15-4-55-12-4 to respect the EPP except for tRFC which appears very sensible @1066Mhz...

My idea here is to understand better the sensibility level of the 4 timings tRRD tRFC tWR tRTP, specially for my P5B-E which appears very limited !

[G.SKILL]

the default value we mean is the setting after clearing CMOS
all you need to set is 5-5-5-15(tCL-tRCD-tRP-tRAS) and keep the others default
for further overclocking, we'd recommend you to try yourself, 'coz every board would perform differently
thanks


G.S

[HiSpeed]

all you need to set is 5-5-5-15(tCL-tRCD-tRP-tRAS) and keep the others default

Sorry, but that doesn't help me to understand what I have to do with tRRD tRFC tWR tRTP when the PC is not stable...

for further overclocking, we'd recommend you to try yourself, 'coz every board would perform differently

I don't want to overclock, only to improve the stability without performance decreasing...

[G.SKILL]

we could make it work without problem with this setting on P5B-E Plus, so we don't think sub-timing would affect the stability
and we do not recommend user to change the sub-timings unless you understand them very well
if there is still problem, please RMA with us
thanks


G.S

[HiSpeed]

we could make it work without problem with this setting on P5B-E Plus, so we don't think sub-timing would affect the stability

It's not a P5B-E Plus but a P5B-E where tRFC and tWR of the last BIOS is probably too tight but I'm not an expert...

we do not recommend user to change the sub-timings unless you understand them very well

I thought it was possible to understand here !

[G.SKILL]

the value in our spd is tighter than the one in the motherboard
and it has to be able to work without problem with default values
so, if it can't run at the setting, please RMA with us
thanks


G.S

[HiSpeed]

the value in our spd is tighter than the one in the motherboard
and it has to be able to work without problem with default values

I repeat again (tRRD-tRFC-tWR-tRTP) :

4-47-12-4 into SPD-EPP @1066Mhz
3-42-6-5 into P5B-E BIOS default (4-42-6-4 manually possible only)
4-56-13-4 into P5E BIOS default

3-42-6-3 into SPD-JEDEC @800Mhz
3-42-6-5 into P5B-E BIOS default
4-56-13-4 into P5E BIOS default

What is tight ?

[G.SKILL]

as we know, EPP can't be enabled on this two motherboards
only nvidia chipset supports EPP
and if you want to run with SPD value, you should enable SPD timing in BIOS
but then you would not see the exact SPD value in BIOS, unless you use some softwares in windows
the timing in SPD only provides sets of timing to make motherboards recognize the memory, it doesn't mean the timing we guaranteed

this model is tested on this two boards but no problem is found while the sub timing is kept default
so, if there is still problem with your memory, please RMA with us
thanks


G.S

[HiSpeed]

Thanks for your reply.

if you want to run with SPD value, you should enable SPD timing in BIOS

In fact, at this step, my understanding is the following:

The SPD contains the minimum values.
When the BIOS default values are smallest, it is better (for stability) to manually change them.
When the BIOS default values are greatest, it is better (for stability) to don't change anything.

Do you agree ?

[G.SKILL]

sorry, but we don't see the relation between these two things....

the SPD contains the minimum values?
the SPD values are based on JEDEC standard, not the timing of our spec
usually they would be looser than the timing of our spec


G.S

[HiSpeed]

the SPD values are based on JEDEC standard, not the timing of our spec
usually they would be looser than the timing of our spec

What are the spec of my RAM (tCL-tRCD-tRP-tRAS-tRRD-tRFC-tWR-tRTP) ?