RAM is confusing

[hk3948]

ive only recently really began to grasp many of the concepts involved in building your own rig and its componenets as i had to do it myself for the first time. RAM (timings, frequency etc) i still find really confusing. am i right in thinking that i want my fsb:dram ratio to be 1:1 or am i way off. and if so, how do i go about changing this

 

[Cob]

Intel machines like to be 1:1 or have the RAM faster than the FSB.

AMD are happy to run the RAM slower than the FSB.

 

[hk3948]

ive got geil pc6400 ram. so, would that ram be fine if i set 1:1 ratio. i have a c2d so fsb is 1066. am i right in thinking this ram can run up to 1600mhz which would require me to have the processor running at 400x9 for the ram to have to be utilised to this extent. is that right. i find it really confusing. trying to get my head around this as am thinking about oc'ing for the first time

 

[Cob]

Intels way of claiming their fsb speeds is confusing. They quad-pump their FSB, so when they say 1066 they really mean 266.

So, yes, to have your PC6400 running at 800mhz (not 1600Mhz) you would need to set your cpu's fsb to 400Mhz at 1:1.

That or you can run the cpu's fsb at its stock 266Mhz and set the memory multiplier to 2.5 (2:3).

 

[ImMrChris]

if i remember correctly to simplify....

CPU FSB is " qaud " pumped ( 4 instructions per cycle or 1 Mhz ) so 1066 / 4 = 266Mhz

and DDR = " Double " data rate ( 2 instructions per cycle or 1 Mhz ) so 800Mhz rated memory really only runs @ 400Mhz as 800 / 2 = 400 of course

correct me if im wrong

it's just a ploy so the manufacturers can blind us with numbers imo

 

[Mole]

Post removed - I was probably talking rubbish

 

[hk3948]

ok, this question prob belongs in the cpu section but prob shouldnt start another thread. the bios for my mobo(evga 680i) doesnt have any options for directly changing the mem clock of the cpu (think thats the 266mhz figure), only lets me change the fsb of 1066. so to get my core to 3ghz for eg, *** value do i need to change the fsb to, is it 1330mhz? im not really sure. and how would this effect my ram. what settings would i need to change for my ram to get optimal results from the overclock. thanks guys. this is confusing for me

 

[davejuk]

if i remember correctly to simplify....

CPU FSB is " qaud " pumped ( 4 instructions per cycle or 1 Mhz ) so 1066 / 4 = 266Mhz

and DDR = " Double " data rate ( 2 instructions per cycle or 1 Mhz ) so 800Mhz rated memory really only runs @ 400Mhz as 800 / 2 = 400 of course

correct me if im wrong

it's just a ploy so the manufacturers can blind us with numbers imo

I 've never made any effort to understand memory timings myself (I'm sure it's not that complicated) but understanding processor and memory speeds isn't too difficult.

1Hz = Once per second
1kHz = 1000 times per second
1MHz = 1 million times per second
1GHz = 1 billion times per second

This is the same whether we're talking about processors, memory, radio waves, or anything else.

Not all processors are created equal. Some may reach twice their stock speed, whilst others are unstable at 120%. It's just luck which you get.

Most BIOS' I've seen allow you to change the FSB using the pre-quad-pumped value (if you follow that), although I believe motherboards made by Intel use a percentage. If yours allows you to change the post-quad-pumped FSB value then it should do so in multiples of 4. Either way, it's the same thing.

 

[ImMrChris]

ok, this question prob belongs in the cpu section but prob shouldnt start another thread. the bios for my mobo(evga 680i) doesnt have any options for directly changing the mem clock of the cpu (think thats the 266mhz figure), only lets me change the fsb of 1066. so to get my core to 3ghz for eg, *** value do i need to change the fsb to, is it 1330mhz? im not really sure. and how would this effect my ram. what settings would i need to change for my ram to get optimal results from the overclock. thanks guys. this is confusing for me

yes to overclock you need to up your FSB it all depends on what other hardware you have in your PC as to how high and stable you can get

there are a lot more " Serious " overclockers on here than me though that do all sorts to their hardware to obtain crazy overclocks, i myself wince at messing with voltages lol

i'd ask in the overclocking forum to get the best advice

 

[WJA96]

ok, this question prob belongs in the cpu section but prob shouldnt start another thread. the bios for my mobo(evga 680i) doesnt have any options for directly changing the mem clock of the cpu (think thats the 266mhz figure), only lets me change the fsb of 1066. so to get my core to 3ghz for eg, what value do i need to change the fsb to, is it 1330mhz? im not really sure. and how would this effect my ram. what settings would i need to change for my ram to get optimal results from the overclock. thanks guys. this is confusing for me

It's actually dead simple on the NVidia boards. You just set the overclocking to unlinked and set your RAM to it's correct timings;

PC4300 - 533
PC5300 - 667
PC6400 - 800
PC7200 - 900
PC8000 - 1000
PC8500 - 1066

Then you dial up your processor FSB which is shown Quad-pumped

CPU speed = FSB x Multiplier

E6300 True Speed = 7 x 266MHz = 1862MHz
E6400 True Speed = 8 x 266MHz = 2128MHz
E6600 True Speed = 9 x 266MHz = 2394MHz
E6700 True Speed = 10 x 266MHz = 2660MHz
X6800 True Speed = 11 x 266MHz = 2926MHz

To convert from NVidia's QFSB to FSB, divide by 4 so 1066/4=266

The reason NVidia have done this is that it gives you an extra 4 steps for click of adjustment so when you need to really fine-tune it, you can get it adjusted a fraction better than you can with an Intel chipset.

So, your query about 3GHz (3000MHz) would depend on which processor you had;

E6300 - 3000/7 = 429FSB, but to convert to QFSB = 429 x 4 = 1718
E6400 - 3000/8 = 375FSB, but to convert to QFSB = 375 x 4 = 1500
E6600 - 3000/9 = 333FSB, but to convert to QFSB = 333 x 4 = 1332
E6700 - 3000/10 = 300FSB, but to convert to QFSB = 300 x 4 = 1200
X6800 - 3000/11 = 273FSB, but to convert to QFSB = 273 x 4 = 1092

 

[hk3948]

another thing i dont really understand is 1t and 2t timing. currently in my bios, its set to 2t. should it be 1t, will it make a difference and what does it mean

 

[EvilGrin]

I'm totally confused by the whole thing too tbh. I really need to make a decision about it all soon as the ram is the only thing holding me back from upgrading!!

Might just bite the bullet and go with Crucal anni's. Don't really wanna spend £200 on ram but meh.