The 1:1 Ratio Question

[Genison]

Thanks to everyone that's responded with feedback to some of my other posts regarding my new system build. Now I'm down to the RAM and I'm trying to understand why a 1:1 ratio is so desired for a setup.

Currently, I've found my setup to fit quite nicely at no more than 3,720 Mhz @ an 8x Multiplier on a 465 Mhz bus. 3.8 fails all the way up to 1.4 v on the core and I don't know if I'm willing to push it past that. Still debating.

Anyway, I could probably achieve the same thing with a 7x multiplier @ 533 Mhz putting my memory at 1066 Mhz and a 1:1 ratio. I did some tests on the previous setup with a 4:5 ratio and a 1:1 ratio. At 8x and 465 Mhz, the 4:5 ratio puts the memory at 1,160 and the 1:1 was 930 Mhz.

In Sandra, it tested the latency of the 4:5 ratio to be about 12 ns faster and the ALU and FPU tests were a good 1,000 points better. Granted, I know these are benchmarks, but that still begs the question of why it's better?

I'm guessing that the 1:1 allows for less latency on the CPU to retrieve data from the memory for the offset of non-synced passes on the clock?? I searched around for any reveiws on this subject or posts in this forum and I basically only found that people said to do it but not for why.

Thanks!!!

 

[cmdrdredd]

1:1 just makes it easier to get high FSb and high CPU speed. This is more important than memory speeds.

 

[darkenedsoul]

I an running with the same CPU but multiplier at 9x and FSB at 412 runs fine at 3.70x but I tweaked it up to 425 and it failed, upped CPU by one notch from 1.4625 and it still failed. I dropped CPU down back to where it was and dropped FSB to 418 and it's still failing Orthos within about a minute. Memory shows 800 830 at that speed, from the earlier tweaks above it was up to 800 850. SPD is at 2.0 as well for 1:1 @800 on 1066 memory and ran fine for 12+hrs on 3 tests (3.6, 3.7, then 3.7 with memory dropped from 5-5-5-15 to 4-4-4-12).

Ideas? I was hoping to get to 3.8 or beyond a tad but not super crazy. I still think 3.7Ghz is pretty respectable at 55c temps at load and around 20c at idle.

 

[myocardia]

Overclocking the FSB is much, much harder with 4 sticks of RAM. If you want to do it, you'll need to give your northbridge chipset a slight bump in voltage. It's called GMCH on your motherboard. You should only need to give it +.1v, to get to 3.8 Ghz.

edit: You'll likely need more vcore, though.

 

[darkenedsoul]

Originally posted by: myocardia
Overclocking the FSB is much, much harder with 4 sticks of RAM. If you want to do it, you'll need to give your northbridge chipset a slight bump in voltage. It's called GMCH on your motherboard. You should only need to give it +.1v, to get to 3.8 Ghz.

edit: You'll likely need more vcore, though.

Hi, I think I have the (G)MCH at +.1v but I'll double check it now. It's at +0.1v already and I did crank up the CPU vcore by a notch and it wouldn't get past 3.730Ghz. It runs pretty quick as it is now. I haven't run 3DMark2006 on it yet. I suppose I will just to see the numbers. But thoughts on it appreciated. As I said I don't want to push it to the limit.

 

[SerpentRoyal]

The easiest way to overclock with four sticks is to use high quality JEDEC 1.8V DDR2 667 or 800 RAMs. These modules have greater working tolerances. Most will not require any tweaking of VTT, NB, or SB. It's best to limit Vdimm to 2.0 or 2.1. You should relax the timing to 5-5-5-15-2T if you intend to overclock more than 10%. I can run two sticks Kingston N5 DDR2 800 at 580MHz or four sticks at 576MHz with no change in Vdimm or timing (5-5-5-18-2T).

The value $10/GB HP DDR2 667 is good up to about 408MHz with 2.0V/5-5-5-15-2T. Four sticks will drop RAM speed to 392MHz with 2.0V/5-5-5-15-2T. No other changes required in BIOS.

 

[darkenedsoul]

Well, I don't have the cash to go dropping on another set of 1Gb 800Mhz DIMM's at this point. Perhaps in hindsight I should have stuck with 800 vs going with 1066, but I did since it was supported (saw it all at correct timings right on power up but voltage was I think at 1.8v vs 2.1). I have it set to 2.1v right now in BIOS. When you talk about overclock are you talking memory or system? At this point I am aware they are two different beasts that sort of go together at some point for those who want to tweak it all. Running now at ~820 per BIOS page on the memory (shows 800 820/830) with FSB at 412. Timings 4-4-4-12 @ 2.1v SPD of 2.0. Ran 12 hrs Orthos CPU/Blend @55C per CoreTemp and SpeedFan/Intel TAT tools all were within a degree of each other.

 

[SerpentRoyal]

Relax the timing to 5-5-5-15-2T should yield higher RAM speed. You only want to bump up NB voltage by one or two settings. Core speed is KING. If you can't can crank up RAM speed to +460MHz @ 4-4-4-12-2T, then go with 1:1 memory divider and the tightest possible RAM timing (2.0-2.1Vdimm).

Spending a lot of $ on overclocking RAMs will only buy an extra 200MHz or so of CPU core speed. That is not a very good return on your investment. A good overclocking chip is FREE and can easily add 200MHz to the core speed.

It's comical to see folks spend big bucks on "high performance" RAMs and PSUs. Think about it. Why would you want to amortized the cost of these components over 5 to 6 years if you're a PC enthusiast? You can get 98% performance by spending 30-40% less $. No need to line the pockets of other people.

 

[darkenedsoul]

Originally posted by: SerpentRoyal
Relax the timing to 5-5-5-15-2T should yield higher RAM speed. You only want to bump up NB voltage by one or two settings. Core speed is KING. If you can't can crank up RAM speed to +460MHz @ 4-4-4-12-2T, then go with 1:1 memory divider and the tightest possible RAM timing (2.0-2.1Vdimm).

Spending a lot of $ on overclocking RAMs will only buy an extra 200MHz or so of CPU core speed. That is not a very good return on your investment. A good overclocking chip is FREE and can easily add 200MHz to the core speed.

It's comical to see folks spend big bucks on "high performance" RAMs and PSUs. Think about it. Why would you want to amortized the cost of these components over 5 to 6 years if you're a PC enthusiast? You can get 98% performance by spending 30-40% less $. No need to line the pockets of other people.

Ok, can you explain then what I should try? Currently it is showing I think about 800 82x at SPD 2.0. I could bump that to 2.40 and run the test to see if it gets beyond a minute or so when it was failing at faster FSB (425 and 418 didn't work nor did 415). I have ram at 4-4-4-12 now as it was before and ran 12 hrs of Orthos previously with no glitches. I am new to all this stuff if you can't already tell ;-) so explain it so a noob like me can understand better. ;-)

 

[SerpentRoyal]

I'd keep 4-4-4-12-2T timing with 1:1 memory divider. Check for stability with 2.0 or 2.1V. Next step is to try 1:1.20 memory divider. For example, if your RAM is running at 400MHz FSB with 1:1 memory divider, then your FSB speed = RAM speed. With 1:1.20 memory divider, your RAM speed will be 400 x 1.20 or 480MHz. That may be too much for the RAM to handle at 4-4-4-12-2T. So you must now increase Vdimm from 2.0 to 2.1V. Run Memtest86, test #5 for 50 loops to check for error. If you can pass 2 hours of Orthos, then the system is probably stable.

You can download and launch CPUz in windows to check your FSB speed and your RAM speed. The Corsair may be rated at higher operating voltage, but I prefer to limit Vdimm to 2.0 or 2.1V.

Inferior RAMs may also require a small bump in NB voltage. Try upping by one or two notches. DO NOT overvolt because the extra voltage can de-stabilize the system.

 

[The-Noid]

The simple answer is speed will always win out over timings. Otherwise DDR3 would be terrible.

As for you Serpent and your "theories."

5/4 == 1.2 wow.

You mean the 1:1.25 divider since the OP is talking about the 4:5 divider.

Also with the price of Crucial DDR2 which is Micron D9GMH/D9GKX under $100 on the eggy, how can you still possibly be recommended these Kingston modules?

I guess for the price I would rather either have ram rated at 1000/1066 or 800C4. Since Crucial is owned by Micron I would guess they know the tolerances of their IC's better than the re branded N5's that Kingston uses.

 

[The-Noid]

Originally posted by: SerpentRoyal
The easiest way to overclock with four sticks is to use high quality JEDEC 1.8V DDR2 667 or 800 RAMs. These modules have greater working tolerances. Most will not require any tweaking of VTT, NB, or SB. It's best to limit Vdimm to 2.0 or 2.1. You should relax the timing to 5-5-5-15-2T if you intend to overclock more than 10%. I can run two sticks Kingston N5 DDR2 800 at 580MHz or four sticks at 576MHz with no change in Vdimm or timing (5-5-5-18-2T).

The value $10/GB HP DDR2 667 is good up to about 408MHz with 2.0V/5-5-5-15-2T. Four sticks will drop RAM speed to 392MHz with 2.0V/5-5-5-15-2T. No other changes required in BIOS.

Just a quick FYI.

1.) There is no such thing as Kingston N5 memory. Certain sets of valueram contain Micron D9GMH/D9GKX which has been rebranded.

2.) If you change your voltage from 1.8v to 2.0v, you will:
A.) No long have JEDEC standard memory. JEDEC standard is for the voltage of 1.8v +-.1v. This argument is a moot point.
B.) Have voided your warranty. If you purchase overclocking memory you at least have a warranty.

3.) You can not generalize valueram. That is why it is "valueram." It is rated at the timings of 667. Just because Serpent was lucky does not mean others will. If you want to run 400 fsb you need to get PC2-6400 as a minimum. This is simply logic.

 

[SerpentRoyal]

That's your interpretation. There is no "sure-thing" when one overclock PC components. That includes major components like CPU, MB, and RAMs.

Here's another lucky soul with "Kingston DDR2 667 Value RAM overclocks easily to 800Mhz even at stock 1.8V". That's a 20% overclock with no increase in Vdimm. I'd rather take my luck with Kingston N5 than your "sure thing" OCZ DDR2 800.

http://forums.anandtech.com/me...word1=kingston+ddr+667



"If you want to run 400 fsb you need to get PC2-6400 as a minimum. This is simply logic"

Let's see...more $10/GB 1.8V DDR2 667 RAMs that will do 400MHz. The world has gone mad because there are so many "lucky" valueram owners @ 400MHz FSB with DDR2 667!

http://forums.anandtech.com/me...AR_FORUMVIEWTMP=Linear

 

[Quiksilver]

Originally posted by: Yoxxy
1.) There is no such thing as Kingston N5 memory. Certain sets of valueram contain Micron D9GMH/D9GKX which has been rebranded.

http://www.valueram.com/datasheets/default.asp

KVR667D2N5/1G
KVR667D2N5/1GBK
KVR667D2N5K2/1G
KVR800D2N5/1G
KVR800D2N5/1GBK
KVR800D2N5K2/1G

....and that is just the 1 gig modules.

 

[darkenedsoul]

Originally posted by: SerpentRoyal
I'd keep 4-4-4-12-2T timing with 1:1 memory divider. Check for stability with 2.0 or 2.1V. Next step is to try 1:1.20 memory divider. For example, if your RAM is running at 400MHz FSB with 1:1 memory divider, then your FSB speed = RAM speed. With 1:1.20 memory divider, your RAM speed will be 400 x 1.20 or 480MHz. That may be too much for the RAM to handle at 4-4-4-12-2T. So you must now increase Vdimm from 2.0 to 2.1V. Run Memtest86, test #5 for 50 loops to check for error. If you can pass 2 hours of Orthos, then the system is probably stable.

You can download and launch CPUz in windows to check your FSB speed and your RAM speed. The Corsair may be rated at higher operating voltage, but I prefer to limit Vdimm to 2.0 or 2.1V.

Inferior RAMs may also require a small bump in NB voltage. Try upping by one or two notches. DO NOT overvolt because the extra voltage can de-stabilize the system.

How would I get 1:1.20? The next step up in the SPD multiplier is 2.40, then 3.20 (which shows up as 1280 and not stable). This is 1066 I'm running at 4-4-4-12 @2.1v running at 1:1 SPD 2.0.

 

[SerpentRoyal]

If 3.20 yields 1280, then try the next lower memory divider. It can be very challenging to run RAM at 533MHz speed/4-4-4-12-2T using P35 platform. You may need to tweak NB and SB along with Vcore and Vdimm. The swet spot is up to about 450-480MHz/4-4-4-12-2T.

 

[The-Noid]

Originally posted by: QuiksilverX1

Originally posted by: Yoxxy
1.) There is no such thing as Kingston N5 memory. Certain sets of valueram contain Micron D9GMH/D9GKX which has been rebranded.

http://www.valueram.com/datasheets/default.asp

KVR667D2N5/1G
KVR667D2N5/1GBK
KVR667D2N5K2/1G
KVR800D2N5/1G
KVR800D2N5/1GBK
KVR800D2N5K2/1G

....and that is just the 1 gig modules.

N5 is the model number. Serpent thinks they are an IC made by Kingston. Kingston can use any IC that screens at this speed. This is what I mean.

 

[SerpentRoyal]

One can break down Kingston's DDR2 800 into three major tiers...non-N5, N5, and HyperX.

non-N5...
http://www.newegg.com/Product/...x?Item=N82E16820134488

N5...
http://www.newegg.com/Product/...x?Item=N82E16820134117

N5 RAMs should cost more $, because of the higher quality ICs.

Care to provide data to support your claim?
"Serpent thinks they are an IC made by Kingston"

 

[myocardia]

Originally posted by: darkenedsoul
How would I get 1:1.20? The next step up in the SPD multiplier is 2.40, then 3.20 (which shows up as 1280 and not stable). This is 1066 I'm running at 4-4-4-12 @2.1v running at 1:1 SPD 2.0.

Actually, with your motherboard, 1:1.20 is 2.40x. Gigabyte uses the DDR equivalent, instead of the actual RAM speed, and 2.4/2= 1.20.

 

[darkenedsoul]

I may try going back to 5-5-5-15 and up it to 2.40 and see if things are stable. I have not been able to run either of the memtest+86 tools I found (1.70 and a 3.3 version of +86) as it gets to: Loading......... and just sits there. But Orthos ran 12hrs no problem in CPU/Blend test with my current settings. Guild Wars runs fine as well.