Question about ddr2 RAM

[zabih107]

Hello community,


I currently have 4GB Kingston 800MHz DDR2 RAM. My MOBO IS xfx Nforce 750i SLI. I also have a core 2 quad q6600 2.4GHz overclocked to 2.8GHz.


I was reading around and found out that ddr2 800MHz REAL speed is 400MHz, so in order to get full use of ram i need my FSB to run at 400 (9*400 = 3.6GHz).

But i only overclocked my processor to 2.8GHZ (9*311 = 2.8GHz). So does this mean that My pc is not using the full potential of the 800 MHz ran that i have?


Another question, lets say i wanted to overclock processor past 3.6 GHz, that means my FSB is higher than ram, is that going to cause problems to the system or no just the ram gona be bottlenock thats all?

Also is it better to have FSB same as ram speed (400MHz) , or lower, or doesnt matter at all?

If you guys could clear these questions up for me then plz do so, also I am not a skilled overclocker so plz dont give me really complex answers and keep it simple.

Thank you in advance

 

[spentshells]

depends on your memory divider you may be just be running it at default speeds
usualy you would want 2:1 like you are showing in your post but I dount you will get that overclock on your MB

 

[jsc]

OK. First of all, there is no real benefit to overclocking RAM. I always recommend setting the RAM clock to twice the FSB frequency. For a Q6600 with an FSB of 266 MHz on an nVidia board (everyone seems to use a different BIOS setup), I set the RAM clock to twice the FSB frequency or 533 MHz. Each bus cycle generates 2 RAM clocks (DDR2 remember?) and 4 bus clocks (quad pumped bus). That's where the 1066 MHz comes from. Notice the distinction between "cycle" and "clock".

As you raise the FSB frequency, the RAM clock will go up pretty quickly. At 3.3 GHz, the FSB freq will be 367 MHz and the RAM clock will be 733 MHz.

This should be your first stop.
Core2 Overclocking Guide - generic guide
http://www.tomshardware.co.uk/forum/259899-11-core-overclocking-guide

Next stop should be a guide for your particular motherboard. Google is your friend.

Also check this -680i overclocking guide - a 750i is just a 600i that has been modified to be Yorkfield (45 nm quad core) compatible:
http://pc.ign.com/articles/747/747606p3.html
I think it's pretty good except for the advice about setting the memory frequency.

Go through the guides. Then take your core voltage off Auto and set your memory voltage to factory recommended values. Change the System Memory Multiplier (or whatever your BIOS calls it) from AUTO to 2.00, 2.00B, or 2.00D - whichever you need to set the Memory Frequency to twice the FSB. Then when you increase the FSB, the memory clock will rise in in proportion with it. At an FSB of 266 MHz, your memory clock should be at 533 MHz.

Download CPU-Z to check your FSB:RAM ratio. It should be a 1:1 ratio.

You should be able to reach 3.0 GHz with the stock cooler. Anything higher and you will need better cooling. For reviews of coolers:
http://www.frostytech.com/top5heatsinks.cfm

For suggestions about how to apply thermal compound:
http://benchmarkreviews.com/index.php?option=com_content&task=view&id=170&Itemid=1&limit=1&limitstart=0

You may or may not be able to reach 3.6 GHz. The chances of going past that with stability are very small.

Keep in mind that these are guides, not cookbooks. YMMV. Because of all the variables, you may not do as well as someone else with a similar system. Or you might do better.
----------
Overclocking since 1978 - Z80 (TRS-80) from 1.77 MHz to 2.01 MHz

 

[jsc]

Spentshells, you're a little confused.
The usual way of determining FSB:RAM ratio is to run CPUZ. CPUZ bases its calculations on comparing FSB freq with RAM freq not RAM clock. So an FSB freq and a RAM clock twice that is a 1:1 ratio.

 

[baracubra]

just unlink your ram freq from fsb, and manually set the desired ram speed. Thats what I did when i OC-ed my Q6600 to 3.8 (fsb 423). Unfortunatelly, it ran too hot so I dropped down to 3.6 and set my RAM to sync mode. Now its running at 400mhz x 2 so the final speed is 800mhz

 

[zabih107]

OK. First of all, there is no real benefit to overclocking RAM. I always recommend setting the RAM clock to twice the FSB frequency. For a Q6600 with an FSB of 266 MHz on an nVidia board (everyone seems to use a different BIOS setup), I set the RAM clock to twice the FSB frequency or 533 MHz. Each bus cycle generates 2 RAM clocks (DDR2 remember?) and 4 bus clocks (quad pumped bus). That's where the 1066 MHz comes from. Notice the distinction between "cycle" and "clock".

As you raise the FSB frequency, the RAM clock will go up pretty quickly. At 3.3 GHz, the FSB freq will be 367 MHz and the RAM clock will be 733 MHz.

This should be your first stop.
Core2 Overclocking Guide - generic guide
http://www.tomshardware.co.uk/forum/259899-11-core-overclocking-guide

Next stop should be a guide for your particular motherboard. Google is your friend.

Also check this -680i overclocking guide - a 750i is just a 600i that has been modified to be Yorkfield (45 nm quad core) compatible:
http://pc.ign.com/articles/747/747606p3.html
I think it's pretty good except for the advice about setting the memory frequency.

Go through the guides. Then take your core voltage off Auto and set your memory voltage to factory recommended values. Change the System Memory Multiplier (or whatever your BIOS calls it) from AUTO to 2.00, 2.00B, or 2.00D - whichever you need to set the Memory Frequency to twice the FSB. Then when you increase the FSB, the memory clock will rise in in proportion with it. At an FSB of 266 MHz, your memory clock should be at 533 MHz.

Download CPU-Z to check your FSB:RAM ratio. It should be a 1:1 ratio.

You should be able to reach 3.0 GHz with the stock cooler. Anything higher and you will need better cooling. For reviews of coolers:
http://www.frostytech.com/top5heatsinks.cfm

For suggestions about how to apply thermal compound:
http://benchmarkreviews.com/index.php?option=com_content&task=view&id=170&Itemid=1&limit=1&limitstart=0

You may or may not be able to reach 3.6 GHz. The chances of going past that with stability are very small.

Keep in mind that these are guides, not cookbooks. YMMV. Because of all the variables, you may not do as well as someone else with a similar system. Or you might do better.
----------
Overclocking since 1978 - Z80 (TRS-80) from 1.77 MHz to 2.01 MHz

thnaks for the great advice jsc really appreciate it, but lol to be honest i didnt get most of what u said , like i said im very new to overclocking ( i just yesterday overclocked my q6600 to 2.8 GHz) . Iwasnt really overclocking my RAM I just have a few question in my head to clear things up about RAM stuff. My question was that lets just say if I raise FSB of cpu to 400 MHz ( 400*9 = 3.6 GHz) , Then does that mean that my RAM is running at 800MHz ( is that 1:1 ratio?)

 

[zabih107]

What I am predicting here is that as long as I my FSb is equal to or under 400MHz, I should NOT worry about my Ram since its ddr2 800MHz. And I am also predicting that if I go FSB over 400 MHz, then the RAM will be probably bottlenecking the system?

tell me if I am right..

 

[zabih107]

also there is an option in the BIOS called "spread spectrum" , and it is enabled, should i disable that? and also "intel speedstep Technology" , should i disable that too?

 

[spentshells]

Spentshells, you're a little confused.
The usual way of determining FSB:RAM ratio is to run CPUZ. CPUZ bases its calculations on comparing FSB freq with RAM freq not RAM clock. So an FSB freq and a RAM clock twice that is a 1:1 ratio.

depends how you have your ram linked to your FSB its really simple

1:2

1333mhz FSB is 666/7 mhz ram uh so yeah I guess I did write it wrong oops

 

[55Range]

also there is an option in the BIOS called "spread spectrum" , and it is enabled, should i disable that? and also "intel speedstep Technology" , should i disable that too?

DOnt disable intel speedstep, it will automatically decrease your frequency by using a lower multiplier, for eg, 400 * 8 as normal clock, eist will use 400 * 6 to save power, create less heat and also lower voltages. Which means when ur pc doesnt require the full power, it will save yu in tems of electricity usage. As soon as power is needed, it will run at a higher multilier (thus *8) I keep EISt on with no probem as for spread spectrum, its advised to turn it off on oCed systems..
So , disable spectrum enable EIST, hope i cleared ur doubts.

 

[zabih107]

DOnt disable intel speedstep, it will automatically decrease your frequency by using a lower multiplier, for eg, 400 * 8 as normal clock, eist will use 400 * 6 to save power, create less heat and also lower voltages. Which means when ur pc doesnt require the full power, it will save yu in tems of electricity usage. As soon as power is needed, it will run at a higher multilier (thus *8) I keep EISt on with no probem as for spread spectrum, its advised to turn it off on oCed systems..
So , disable spectrum enable EIST, hope i cleared ur doubts.

thanks , it cleared out my doubts. In my mobo it is the opposite lol spread spectrum is enabled while EISt is disabled, so i just do a switcheroo there. Also another question :

the normal speed of q6600 is 2.4GHz, lets say i overclock it to 3.6GHz ( which Iam planning to do so) , how much do i have to raise my voltage to to run it stable? (I am sorry I dont know the stock voltage of it right now and the safe range that intel suggests). thank you!

 

[55Range]

thanks , it cleared out my doubts. In my mobo it is the opposite lol spread spectrum is enabled while EISt is disabled, so i just do a switcheroo there. Also another question :

the normal speed of q6600 is 2.4GHz, lets say i overclock it to 3.6GHz ( which Iam planning to do so) , how much do i have to raise my voltage to to run it stable? (I am sorry I dont know the stock voltage of it right now and the safe range that intel suggests). thank you!

Whenever u overclock, voltage[vcore] should only be set a little higher, its trial and error, all cpu are different, try an increase in fsb with a small increase in vcore.
Intel suggests a value of vcore that should not be exceeded, check it out for your cpu,. Also, with higher overclocks, thus higher vcores, cpu will produce considerably more heat, a cpu cooler will be needed-
And dont forget to stress test to be sure, prime 95 or OCCT will do that.

 

[55Range]

Btw, intel suggests [VID Voltage Range 0.8500V-1.5V] for your processor.

http://ark.intel.com/Product.aspx?id=29765
Whatever overclock u do, dont exceed that, it might well damage your processor if exceeded..

 

[zabih107]

K thanks 55range, and yes i will be getting a cpu cooler (hyper 212 plus) so i can overclock well. ALSO when in cpu-z or BIOS i check the processor info , it shows core voltage jumping between 1.304v and 1.206v. Like it goes back and forth between those two voltages, so I am not sure which voltage the processor is currently running on, im guessing the higher one (1304 v) ?

 

[zabih107]

Best answer selected by zabih107.