Phenom II ddr III speed vs timings

[charged3800z24]

I have been testing my Kingston Hyper-X 1800 modules and so far have 1.7v and cas 7 @ 1600mhz. What do you think Chew*? I think it is good settings, I usually have my NB @ 2400 and CPU higher, but wanted to make sure any errors were infact the memory.

[Tony]

Remember phenom am2 had a 1066 mode...things slowed down to do 1066 and you had to force NB clock higher to claw back performance. Am3 has the same issue when you go to 1600, the only issue is you need to jump to 3000MHZ on the NB to gain the performance back, 2800 and 2600 show no difference from my testing here.

So 1333 6-6-6-24 is the sweet spot, 2600MHZ NB and 2600HT, easy clock with 1.6 to 1.65V ram and the CPU will probably go a few MHZ higher also due to less strain.

You don't need high ram with AM3...for 24/7 its not worth the effort

[charged3800z24]

Remember phenom am2 had a 1066 mode...things slowed down to do 1066 and you had to force NB clock higher to claw back performance. Am3 has the same issue when you go to 1600, the only issue is you need to jump to 3000MHZ on the NB to gain the performance back, 2800 and 2600 show no difference from my testing here.

So 1333 6-6-6-24 is the seet spot, 2600MHZ NB and 2600HT, easy clock with 1.6 to 1.65V ram and the CPU will probably go a few MHZ higher also due to less strain.

You don't need high ram with AM3...for 24/7 its not worth the effort

So I should try for 1333 and even tighter timings? I think I can get below 1.7v at that speed and CAS 6, what do you think?

[shaolin95]

I totally agree with Tony as I was playing with my RAM today and found out exactly what he is stating her abour the NB at 2800 not doing much when running 1600.

[charged3800z24]

I totally agree with Tony as I was playing with my RAM today and found out exactly what he is stating her abour the NB at 2800 not doing much when running 1600.

I am going to try and recreate this with wprime, 3dmark CPU score, WinRAR. with lower RAM and tighter timings. You got me currious.

[shaolin95]

I also used pcmark, vantage and crysis CPU test.

[roofsniper]

ehhh im still buying 1600 ram but i might just downclock it if its better.

[charged3800z24]

I will run more test after wife goes to bed, well maybe

Here is what I did with 2000NB. the CPU is clocked 3.4 do to my AOD profile loading with wPrime ( I was testing rpofiles and have changed it). what I noticed was wPrime actually looked to do better, Pi was about the same, and WinRAR fell some. I will raise the NB higher and run test again.

First is 1333 6.6.6 21



Second is 1600 7.7.7 23

[roofsniper]

im curious how this affects real world performance like games and other programs for example. seems like winrar would be a better test than pi or prime would be. its interesting to see this tho. with ddr2 there was no wall and the highest frequency you could get was always the best performance. now with ddr3 theres a wall right in the middle where if you go too high you get lower performance. wonder if as the imc on the cpu advances if this will change and end up like ddr2. what happens when you run 1333 at c7? similar to 1600 at c7?

[crazydiamond]

i just see this as the nb is bottlenecking the ram and w/ higher nb speeds it would show improvements for higher speed ram... hopefully between bios and imc improvements we will start to see 3000mhz+ nb on air regularly

[shaolin95]

interesting point indeed...I cant achieve 3000 unfortunately to test this.

[charged3800z24]

interesting point indeed...I cant achieve 3000 unfortunately to test this.

I can only hit 3000nb on my 940. Both 720's have a 2800NB max and 2600 is most stable. I am going to keep my 1600 CAS 7 @ 1.7v. It has the best overall performance so far regaurdless of test.

[chew*]

interesting point indeed...I cant achieve 3000 unfortunately to test this.

I will be testing 3000 + nb in the next few days...........but as I stated before for those on air/water its pointless to get High speed ram unless you have plans to go sub zero........

[demonkevy666]

I can only hit 3000nb on my 940. Both 720's have a 2800NB max and 2600 is most stable. I am going to keep my 1600 CAS 7 @ 1.7v. It has the best overall performance so far regaurdless of test.

at what voltage ? mine needs to much like 1.625 volts and I've only done it once.

[chew*]

Highest I have done on air was 3200 IIRC, on the DS4H and I pushed it hard very hard to do so.....

[charged3800z24]

at what voltage ? mine needs to much like 1.625 volts and I've only done it once.

the 720's need 1.45 for 2800. it took the same on the 940 to hit 3000nb. The 940 is on the asus M3A79-t the 720's are both on MA790FXT-UD5P boards. I used f3L bios. I am back on f3B for some 4core loving. 2600NB is all I can get right now.

[charged3800z24]

Highest I have done on air was 3200 IIRC, on the DS4H and I pushed it hard very hard to do so.....

that is pretty impressive. I never tried for more then 3000NB.

[chew*]

The gigabyte needs the NB fixed atm for 955's, thats why you see me running 2600 on it......taking +.300 to do that and it shouldn't, the msi is doing 2800 right now at 1.32 for comparison.........

[charged3800z24]

The gigabyte needs the NB fixed atm for 955's, thats why you see me running 2600 on it......taking +.300 to do that and it shouldn't, the msi is doing 2800 right now at 1.32 for comparison.........

wow, I need a 955, I wonder when that will be fixed on the Gigabyte? I don't really wanna buy another board

[demonkevy666]

the 720's need 1.45 for 2800. it took the same on the 940 to hit 3000nb. The 940 is on the asus M3A79-t the 720's are both on MA790FXT-UD5P boards. I used f3L bios. I am back on f3B for some 4core loving. 2600NB is all I can get right now.

was that in XP, cause I'm vista 64 bit remember.

too bad gotvoltlage isn't in here with his results form his 9950 from 2700mhz NB and higher and low memory.

[chew*]

wow, I need a 955, I wonder when that will be fixed on the Gigabyte? I don't really wanna buy another board

Very soon I hope, If not I will give them a nudge and show screenies and voltages required to do x and the same ram at higher clocks on another board to show them the light........

Yes I prefer to use them but I'll be the first to call them on an issue as well, a few betas work fine......I want the public to work fine........

Fanboys don't get anything fixed, dirgruntled end users do.

[charged3800z24]

was that in XP, cause I'm vista 64 bit remember.

too bad gotvoltlage isn't in here with his results form his 9950 from 2700mhz NB and higher and low memory.

win xp 32 and win 7 32.

[roofsniper]

well see how it works out with a high nb. the ram controller is speced for 21 GB/s and 2 sticks of 1333 is slightly over 21 GB/s. 2 sticks of 1600 would be 25.6 GB/s. dont know if i am calculating it right but to get full performance out of 2 sticks of 1600 you would need the nb to run at about 2.7ghz. try something like that and see how it performs then.

[demonkevy666]

well see how it works out with a high nb. the ram controller is speced for 21 GB/s and 2 sticks of 1333 is slightly over 21 GB/s. 2 sticks of 1600 would be 25.6 GB/s. dont know if i am calculating it right but to get full performance out of 2 sticks of 1600 you would need the nb to run at about 2.7ghz. try something like that and see how it performs then.

this reminds me I once said your memory speed is best at half of your Nb speed. and that's extremely close, even if is rounded off.
which would mean you would need 3.6ghz NB for 1800mhz memory.

[chew*]

well see how it works out with a high nb. the ram controller is speced for 21 GB/s and 2 sticks of 1333 is slightly over 21 GB/s. 2 sticks of 1600 would be 25.6 GB/s. dont know if i am calculating it right but to get full performance out of 2 sticks of 1600 you would need the nb to run at about 2.7ghz. try something like that and see how it performs then.

We've already tried it..........wouldn't post info like this if we hadn't.........that why I said 1600 is useless for air/water.......you need 3000nb + and cpu speeds in excess of 4+ as well....it scales linear yes, but not at speeds doable 24/7air/water.

At 6.2g 4000+ NB we tested 1800 7-7-7 versus 1700 9-9-9 11.078 PI versus 11.02x we lost screenie of the 11.02x...........the difference is very very slight..........really need 1800+ 6-6-6 to low volt stuff to scale.....with 4000 + NB.............

If you remember msimax compared 3 boards as well 2600 NB was faster with 1600 ram than 2800 was.......