Corsair TWIN2X2084-6400C4

Ronin13

Senior member
Aug 5, 2001
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I just finished a build with these parts:

Antec P150
ASUS P5B-E Plus (965e chipset)
Conroe E6600
Corsair PC6400C4 RAM, 2 GB
WD3200KS SATA hard drive
Plextor 760 SATA DVD burner
eVGA 8800 GTS
X-Fi Xtreme Gamer

(Except at the moment it's an IDE hard drive, as the SATA one was DOA.)

When I check CPU-Z, it tells me that the Corsair's SPD timings are 4-4-4-12, which is also printed on the side of the DIMMs.

But when I in the BIOS enable 'use SPD timings', the RAM runs with these settings: 5-5-5-18.

If I disable 'use SPD timings' - thus getting the chance to choose them myself - and I put in 4-4-4-12, the system boots up fine, but the few benchmarks I've tried to run (3dMark and Aquamark) all terminate prematurely with failure messages.

This X-bit labs review has the following text:

To ensure that these memory modules are compatible with different mainboards, there are two work modes listed in the standard PSD field: with 4-4-4-13 timings and 533MHz frequency and 5-5-5-18 timings and 800MHz frequency. However, these numbers do not actually reflect the real capabilities of the Corsair TWIN2X2048-6400?4 memory kit. The manufacturer suggests that you should check out the potential of this solution in the EPP section. This section serves to automatically set up the memory subsystem of platforms built around any Nvidia nForce 500 chipsets based mainboards. This is where we come across the DDR2-800 mode with 4-4-4-12 timing settings that should work at 2.0V Vdimm, according to EPP.

1: What is the 'EPP section'?

2: Is this only supposed to work with the nForce 500 chipset?

3: How do I enable the 'Enhanced Performance Profile'?
 

Idontcare

Elite Member
Oct 10, 1999
21,110
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91
There are tons of more qualified people on this board to help you out, but my understanding is that the JEDEC standard (the people who defined what SPD is and does) was defined as 5-5-5-18.

So if you want your sticks to run per SPD, vis-a-vis JEDEC standards, then it will run at 5-5-5-18.

A product spec, 4-4-4-12, versus an SPD setting, 5-5-5-18, are two different things. (to my knowledge)
 

Dahak

Diamond Member
Mar 2, 2000
3,752
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1) EPP Section - In the chip that stores the SPD information to run the chips at the timings that are specificed, nvidia has used some of the unused memory area to store these Enhanced Preformance Profiles.

2)As far as I remember, the EPP will only work on nforce 5 and maybe the new nforce 600 series chipsets.

3)Only works on nvidia 5 and 600 series chipsets, as far as I know

As for getting to run at the faster timings, you would have to turn off the SPD and set it manually. Aslo what you may need to do is increase the VDIMM voltage as well to get them to run stable. Should be safe to bump the VDIMM voltage up to 2.0v as the memeory is rated to run that

 

Juno

Lifer
Jul 3, 2004
12,574
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so i have an asus m2n-sli deluxe board with nforce 570 chipset, will i be able to change the timings?
 

Ronin13

Senior member
Aug 5, 2001
374
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Originally posted by: Dahak
As for getting to run at the faster timings, you would have to turn off the SPD and set it manually. Aslo what you may need to do is increase the VDIMM voltage as well to get them to run stable. Should be safe to bump the VDIMM voltage up to 2.0v as the memeory is rated to run that
I increased the voltage to 2.0 and it seems to be stable at that setting. Are there any risks associated with such an increase?

(I must admit that I find it a little odd that the RAM doesn't run at is rated 4-4-4-12 timings without this kind of intervention. I mean, it's printed on the DIMMS, CPU-Z says these are the SPD timings, yet when I tell the mobo to enable SPD timings, I get 5-5-5-18. If I hadn't seen that X-bit labs review, I wouldn't have known anything about there being different SPD settings...)

 

Dahak

Diamond Member
Mar 2, 2000
3,752
25
91
Ronin13 - You should be safe running them at the 2.0v as sticks are rated to run at that speed as well, if they fail which i dont forsee, should be fine under warranty as your are running them at rated spec, now if you had it at like 2.5 or some over spec then no.


Juno, yes would still beable to change them. the epp is like the spd on the ram, if you have a compatible board it will automatically use that vs the spd
 

Juno

Lifer
Jul 3, 2004
12,574
0
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thanks, i just downloaded cpu-z to see the timings and it showed 4-4-4-12 timings. i'm thinking about lowering it..
 

Ronin13

Senior member
Aug 5, 2001
374
0
76
Thanks!

Since my RAM currently is running 4-4-4-12 stable at 2.0v (as in the EPP you can see in the link from the first post), would there be any reason to increase the voltage to 2.1?
 

Larsdidriksen

Junior Member
Jan 5, 2007
1
0
0
the Ram in that Review is NOT the Ram you will get today. Corsair changde the IC's from Micron D9 (wich is used in most ddr2-8500 including corsairs own) to Promos chips wich will not come close to the test results. the Promos chip is worth toiletpaper.

if you want to be sure to get good results, make sure you get corsairs early version ram. ddr2-6400c4 v.1.1 and 1.2 shoul be safe, anything else is Promos and youd be better of getting value Ram. Either that or get the DDR2-8500, same Ram

i made the same mistake, I thought I was a super Ram block. Man was i disapointed when the heat sink came off. Promos chips dont OC well, sometimes not at all. Tjek
Corsair list of chips used in there ram

Micron is the best chip you can get, and is used in most high end Ram, Corsair use to use them, but have change to a cheper (and really bad) chip, from Promos.