[Dopamin3]

I see many people asking questions about AMD memory settings and would like to post this guide as great information regarding the AM3 platform and memory. It has been very useful to me, especially because I really couldn't run 1600mhz stable. Mods you should sticky this as it is such a great read.

I did not make this guide and take no credit for it, please give a big thank you to Tony over at OCZ Technology.

Here we go guys:

With popularity growing for AM3 and people looking to squeeze every last drop of performance from their Black Edition CPU i though i would investigate the best way to set up a system and see just which method of running the memory was faster.

Most feel higher numbers = better, so 1600MHZ ram should be better than 1333MHZ ram...prepare to be shocked and pleased all at the same time!

The key to Phenom 2 performance is the NB clock or memory controller clock, it is shown in the bios on most boards as CPU-NB or memory controller and has its own multiplier adjustment all of its own.

Stock speed is 2000, but this is FAR FROM BEST...you really do need to consider 2600MHZ or higher for you to get the best from your system.
So lets see my results and i will explain where you need to focus your tweaking efforts.

1333 6-6-6-24 1T and 1600 7-7-7-24 1T but with the NB-CPU clock at 2000, 2200, 2400, 2600, 2800 and 3000 with CPU @ 3.8GHZ as this is where the bulk of air and watercooled rigs will land.
Tests are super pi 32m and AutoGK encode DVD FILM 720X480 800MB VOB up scaled to 1280x960 AVI 160MP3 sound 350MB file.

time is converted to seconds for both test, lost the decimal places off PI as they were not needed

TEST WITH RAM AT 1333 6-6-6-24 1T

TEST WITH RAM AT 1600 7-7-7-24 1T

1333 RAM RESULTS:
32M pi 35secs faster with NB clock at 3000 over 2000
encode 47secs faster total job NB clock at 3000 over 2000

1600 RAM RESULTS
32M Pi 36 secs faster with NB at 3000 over 2000
encode 57secs faster total job NB clock at 3000 over 2000

So lets make this easy for you and drop the results on the same graphs

As you see 1333 6-6-6-24 1t is faster than 7-7-7-24 1t for super Pi but slightly slower for encoding. What you need to note though is at around 2400MHZ CPU-NB encode test both 1333 and 1600 are so close its not worth bothering about...after that 1600 is faster as 1333 memory starts to become a bottleneck.

Update May16th 1:25AM...5-5-5-24 1t hits back. you guys looking for 1800MHZ ram at 8-8-8- or 9-9-9- forget it, with the NB around 2400 to 2800MHZ 5-5-5-24 1t 1333 is where you need to be.

And finally adding 6-6-6-24 1t 1600MHZ into the graph...for me 1333 5-5-5-24 1t is best, easier to do with most ram and for me allowed an easier OC on the CPU and the CPU-NB.

Moving on now we have a another domain we can overclock called HT let us see how overclocking this has an effect on 3D performance. 3870X2 Video card, stock clocks. 3dmark vantage
CPU @ 3.8GHZ, CPU-NB@ 3GHZ, RAM @ 1600 7-7-7-24 1t

As you see 2000HT is faster by a mile than 2600HT so leave it at stock speeds...no tweaks needed

Thanks again to Tony for such a great guide

 

[D3TH.GRUNT]

nice guide man, i will definitely be coming back to this again and again

 

[Afrodisiac]

Damn, great info. Thanks for posting, +1.

 

[Bartmasta]

I've seen this guide before.

Anyways, the same applies to DDR2, right? Cause honestly I didn't notice a big difference when overclocking my ram.

 

[Dopamin3]

Quote:

Originally Posted by Bartmasta I've seen this guide before. Anyways, the same applies to DDR2, right? Cause honestly I didn't notice a big difference when overclocking my ram.

It should essentially apply the same way for ddr2. I believe 1066 is very easy to achieve on DDR2 with AMD, so you can still clock your ram higher and increase northbridge speed. I would assume the higher the NB speed the better performance you would get, being similar to the AM3 platform. It should scale similarly.

 

[Bartmasta]

Well I clocked it from 800 5-5-5-16 so 1074 4-5-5-15 is already a lot.

My NB is @ 2617 MHz and I don't to go any higher unless I'm benching. Once I get a new cooler I will be able to increase my HT ref clock higher, but then my HT link would go above 2000, currently 2013.

 

[Dopamin3]

Quote:

Originally Posted by Bartmasta Well I clocked it from 800 5-5-5-16 so 1074 4-5-5-15 is already a lot. My NB is @ 2617 MHz and I don't to go any higher unless I'm benching. Once I get a new cooler I will be able to increase my HT ref clock higher, but then my HT link would go above 2000, currently 2013.

Wow those patriot sticks clock very nicely. I hope you can push higher

 

[eclipseaudio4]

Very nice info! +1 rep and +1 for sticky!

 

[videoman5]

Hmph, my NB is at 2600, but so is my HT. Can you test lower HT speeds to see if 2000 Mhz is really what it should be kept at?

 

[Dopamin3]

Quote:

Originally Posted by videoman5 Hmph, my NB is at 2600, but so is my HT. Can you test lower HT speeds to see if 2000 Mhz is really what it should be kept at?

From what I understand, the default 2000mhz for HT Link is best. According to the last chart, the higher the HT Link is the worse the performance in 3dmark, so I assume it would be similar in other applications. You could do a quick test yourself but I don't think it will be any real world performance gains/losses. Maybe a few points in a benchmark.

 

[djgarygillespie]

Quote:

Originally Posted by Dopamin3 I see many people asking questions about AMD memory settings and would like to post this guide as great information regarding the AM3 platform and memory. It has been very useful to me, especially because I really couldn't run 1600mhz stable.

So I’m torn between the OCZ3P1600LVAM4GK or OCZ3N1800SR4GK
I wanted to underclock the R4GK to get better timings and lower voltage, but it looks like this kit has more issues.
I see that the R4GK is supported on the Gigabyte’s list and the M4GK is not.
So I just wanted to get your options on these two kits.

 

[richierich1212]

So how can we hit 1333MHz speeds with CL5? I thought the fastest 1333MHz available was with CL6?

 

[Dopamin3]

Quote:

Originally Posted by djgarygillespie So I’m torn between the OCZ3P1600LVAM4GK or OCZ3N1800SR4GK I wanted to underclock the R4GK to get better timings and lower voltage, but it looks like this kit has more issues. I see that the R4GK is supported on the Gigabyte’s list and the M4GK is not. So I just wanted to get your options on these two kits.

OCZ3P1600LVAM4GK is much better. They can do 1800mhz at those timings easily providing you're IMC can handle it (most AMD IMC can't handle 1500mhz+). They should be able to do 1700mhz @ 7-6-6-24 with 1.68v

In addition to that, they can clock pretty well with tighter timings. I'm running 6-6-5-20 with ease @ 1333mhz. I'm not very experienced in ram clocking but am getting better.

Quote:

Originally Posted by richierich1212 So how can we hit 1333MHz speeds with CL5? I thought the fastest 1333MHz available was with CL6?

You need a very good kit, probably one of the Animal sets or another highly binned kit.

 

[Slappa]

Quote:

Originally Posted by Dopamin3 OCZ3P1600LVAM4GK is much better. They can do 1800mhz at those timings easily providing you're IMC can handle it (most AMD IMC can't handle 1500mhz+). They should be able to do 1700mhz @ 7-6-6-24 with 1.68v In addition to that, they can clock pretty well with tighter timings. I'm running 6-6-5-20 with ease @ 1333mhz. I'm not very experienced in ram clocking but am getting better. You need a very good kit, probably one of the Animal sets or another highly binned kit.

Generally, the IMC hits a limit on air at around 1650-1700MHz. This can however, be beaten through tuning drive strengths.

 

[Dopamin3]

Updated and added a poll. I meant to put sticky but accidentally wrote stick, please forgive me, and I think you all should understand what I meant.

 

[Dopamin3]

Bump for justice.

I would like to see sticky on this.

 

[filipin0yboi]

can i get a tl;dr plz

 

[Riou]

This was really a good guide buy Tony @ OCZ. I remember reading this over at the OCZ forums.

 

[Dopamin3]

Quote:

Originally Posted by filipin0yboi can i get a tl;dr plz

tl;dr: 1333mhz memory with tight timings and high northbridge frequency is better than 1600mhz with looser timings and stock northbridge frequency.

 

[filipin0yboi]

Quote:

Originally Posted by Dopamin3 tl;dr: 1333mhz memory with tight timings and high northbridge frequency is better than 1600mhz with looser timings and stock northbridge frequency.

thanks! +rep