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CPU Frequency limited due to RAM Frequency?

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Gnr

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Oct 14, 2010
Hi, i have got an Asus P5B with FSB currently at 333Mhz and a Core 2 Duo E6600 @ 3,0Ghz and DDR2-667 RAM.
So I have got a 1:1 RAM divider, because 333Mhz FSB * 2 = 667 Mhz, which is the RAM.

When I now increase the FSB I can't chose a lower RAM than 667Mhz. So I am trapped. I can't increase the FSB because then the RAM would be overclocked, which I don't really want. What I really want is getting a higher CPU Frequency, but that needs a higher FSB which I cannot get. So is there a way out?

Thanks in advance :)
 
Increase the three primary ram timings by one, and the fourth by three, and see how far the ram will OC :D

(So if it's 5-5-5-15 now, make it 6-6-6-18)
 
Alright, thank you, I already realised that there's no other way :)

Is a worse timing and higher FSB better?

Btw, I can't find how much voltage I can put on my DIMMs, Kingstons and Corsairs website's search don't find any of these:

Kingston KTC1G-UDIMM 1 GB DDR2-800 DDR2 SDRAM (5-5-5-18 @ 400 MHz) (4-4-4-12 @ 266 MHz) (3-3-3-9 @ 200 MHz)
Corsair Value Select VS1GB667D2 1 GB DDR2-667 DDR2 SDRAM (5-5-5-15 @ 333 MHz) (4-4-4-12 @ 266 MHz) (3-3-3-9 @ 200 MHz)
 
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Since you don't have any intention of increasing the DRAM frequency, and the RAM is already at DDR3-667 (333MHz FSB w/ a 1:1 FSB : DRAM ratio), your only alternative would be to purchase higher speed RAM. Otherwise take Bob's suggestion and loosen the timings, or bump the DRAM voltage to compensate for the higher frequency.
 
Worse ram timings and higher cpu clock speed will (almost) always give better performance in everything.
 
Thanks, but I am still unsure how much I can increase the voltage of RAM :(
 
Spec for ddr2 in general is 1.8v.
If the ram doesn't say on the sticker on the ram itself, that's probably what the spec is.
You can download CPUz and check the SPD tab, it will tell you if the spec is higher (usually).

Generally speaking, any ddr2 can run 1.9v without issues if you keep it cool.
 
OK, I tried to overclock but quickly ran into problems^^

I only changed the RAM timings from 5-5-5-15 to 6-6-6-18 and couldn't post. Why?

I then tried several timings, I finally was able to post with 5-6-6-18, thats quite what I wanted (6-6-6-18). But why can't I set a higher first timing? Shall I continue increasing the FSB with 5-6-6-18 or isn't that a good configuration?
 
Give a shot and see if it works, if it fails it'll do what it already did when you tried to run 6-6-6-18, it won't kill anything.
Excessive voltage and heat kill things.
 
Why dont you want to overclock your ram?

I want to and I did.

I was able to get FSB 345MHz, means DDR2-790. It passed memtest86+. With 350 FSB I got errors in memtest86+. I used 5-6-6-18 and 5-5-5-15. There was no difference. It passed memtest86+ with 345 FSB and failed with 350 in both cases, so now I'm running on 5-5-5-15 :) because as I already said 6-6-6-18 doesn't post.
I got my CPU to 3,1GHz now, but can't overclock further because of the RAM. Btw, my temperatures when running prime for 2 hours are 42°C, so that would be no problem :(

Any suggestions what I can try?
 
Give the RAM a little voltage bump. If that doesn't work try bumping up the NB voltage.

OCing is more than just vcore and CPU freq. ;)
 
Give the RAM a little voltage bump. If that doesn't work try bumping up the NB voltage.

OCing is more than just vcore and CPU freq. ;)

My RAM voltage is already 2.0V. On the sticker of the 800 MHz RAM it says 2,0V, but I can'T find any information about the 667 MHz RAM.

NB voltage I can't change in the BIOS. Only VCore, FSB Termination Voltage and RAM voltage.
 
The P5B doesn't have NBv? :shrug: I built a rig for a buddy w/ the P5B-Deluxe and it had that option. Oh well.

You should be able to go up +0.1v on the RAM w/o any problems. Have you tried increasing FSB Term to see if that helps any?

Edit: Just noticed that you have 2 completely different RAM sticks. Can you post up a screen shot of CPU-Z showing the SPD tab? You'll have to take 2 screenshots; one for each stick (selectable from a drop-down menu).
 
The P5B doesn't have NBv? :shrug: I built a rig for a buddy w/ the P5B-Deluxe and it had that option. Oh well.

You should be able to go up +0.1v on the RAM w/o any problems. Have you tried increasing FSB Term to see if that helps any?

Edit: Just noticed that you have 2 completely different RAM sticks. Can you post up a screen shot of CPU-Z showing the SPD tab? You'll have to take 2 screenshots; one for each stick (selectable from a drop-down menu).
I compared the manuals on the asus website. P5B Deluxe does indeed have SB, NB etc mentioned. They are missing in the P5B however :(

I tried to increase the FSB Termination, it didn't help.

Screens are in the attachment. ;)
 

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Slots 1 & 2... Are you in dual-channel mode? The Memory tab in CPU-Z will tell you if you're in dual-channel or single-channel. Dual-channel mode is preferred for more performance, but I'm not sure if it's a good idea if you have different sticks like that.

You might want to try OCing w/ 1 stick at a time, so you can find out what each stick is capable of.
 
Slots 1 & 2... Are you in dual-channel mode? The Memory tab in CPU-Z will tell you if you're in dual-channel or single-channel. Dual-channel mode is preferred for more performance, but I'm not sure if it's a good idea if you have different sticks like that.

You might want to try OCing w/ 1 stick at a time, so you can find out what each stick is capable of.

Yes, I am running in dual channel mode. I will try the 6-6-6-18 timings with only 1 DIMM and post what I got :)
 
Okay, I tested 6-6-6-18 with all DIMMs, I always inserted only one of the four. It didn't post with any of them. :( I think I will buy some not so expensive RAM so that I can overclock higher...
 
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