PC2-8500?

[MadFruit]

OK, so I have been out of the game for a while - but there was one thing I thought I understood regarding RAM. PC6400 was for the new AMDs because of the 800MHz FSB and PC8500 was for Intel because of the 1033Mhz FSB. All the other speeds are for overclocked processors/FSBs etc... but at stock speeds, those were the two to have.

I'm clearly wrong. I see nearly everyone on this forum getting PC6400 for their new Core 2 Duo's and I don't know why. I even seen some posts saying there is no point in getting any faster as you wont take advantage of it.

So, is 6400 the budget option RAM for a C2D, but 8500 the best bet, or is there really no difference (I find this hard to believe) or have I just got the whole thing wrong (most likely). Anyone care to explain? I'm thinking of getting a E6600 fairly soon and would like 4Gb to go with it, I just want to make sure I get the right stuff, but I don't pay too much for performance I am not going to notice.

Go easy on me DDR1 had only just appeared the last time I built a machine

 

[Kaiju]

I'm in the same boat mate. Took me a dozen posts to even get close to understanding it.

Okay, so basically you can either run synchronously or asynchronously. With synchronous, whatever the FSB is set at, the CPU and RAM will be set at. At least that's how I follow it.

So if you had a FSB of 400, your CPU speed would be 400 multiplied by it's multiple (E6300's 7x for example, effectively 2.8GHz) and the RAM would be 800MHz (DDR2, so double rate), effectively PC6400 for synchronous 1:1. The tighter the RAM timing is quoted at PC6400, the higher the price (4,4,4,12 opposed to 5,5,5,15) and the better performance.

With all RAM though, you can slack/tighten the timings to run above and below the stock timings. Take the Crucial PC5300 10th anniversary stuff. That's rated at only 667MHz, yet people are able to overclock the stuff above and beyond 1000MHz due to it's Micron D9 chip.

Consequently PC8500 is less appealing as it costs more with only slack timings at stock. As it's also rated at 1066MHz, a 533 FSB running synchronously is something most Conroe's won't manage and the performance advantage of running asynchronously with the memory at 1066MHz is proven to have only slight, if any, performance improvements.

PC8000 would be a better bet at 1000MHz, as a 500FSB running synchronously is achieveable, but again as it's more expensive than PC6400, so the most cost effective product has to be the PC6400 sticks as they can be clocked to PC8000 with relative ease.

Please correct me if i'm wrong guys.

 

[MadFruit]

OK, thanks, that makes things quite a bit clearer, but I am still a little confused on a point.

All the Conroe's say they have a FSB of 1066. You say most conroe's wont make this syncronously - so I presume they run async normally at 1066 - hence when you'd need PC8500 - but this provides little to no performance increase over sync at say 1000?

Assuming the above is true, I think I get it - thanks

 

[Kaiju]

OK, thanks, that makes things quite a bit clearer, but I am still a little confused on a point.

All the Conroe's say they have a FSB of 1066. You say most conroe's wont make this syncronously - so I presume they run async normally at 1066 - hence when you'd need PC8500 - but this provides little to no performance increase over sync at say 1000?

Assuming the above is true, I think I get it - thanks

Conroe is "quad-pumped," (Intel marketing trick), where really the bus speed multiplied by four. So really, the FSB is 266 at stock mate.

 

[christopher]

Hi, sorry for hijacking this thread. But will buying PC8500 be future proofing for when Quadcore prices come down? I see that the Full systems that ocuk sell have PC8500 ram. Or does it work on the same principle as dual core?