Why do memory timeings differ from amd / intel on the same ram?

The_Neon_Cowboy · Sep 26, 2004, 02:15 AM

Why do memory timeings differ from amd / intel on the same ram?

For example I'm looking at some ram some have it has duel times listed others adverise just thier thier intel timeings... I read carefully the feed back on sites that allow it on thier sales page like newegg....

For example a stick of PDP System 512 pc 3200 mb ram
AMD:2.5-3-3-8-T1
Intel:2-3-2-5-T1

Thats a big differance so much I woun't buy the ram. But a big problem they only advertise the intel speeds. Not what they will do on AMD's... Some have duel timeing listed...I don't under stand why the intels will let the ram do better timeings with the exact same stick of ram at the same speed.

drakesteakn · Sep 26, 2004, 02:32 AM

i always wondered that myself.

mkk · Sep 26, 2004, 02:43 AM

Perhaps the integrated memory controller on the Athlon64 line pushes the memory a little bit harder. While I haven't read any technical briefs concerning this it's something that keeps pop'ing up in various reviews. Identical RAM timings in between systems does not indicate identical memory performance, as there is much more to it than that.

The_Neon_Cowboy · Sep 26, 2004, 03:05 AM

Quote:

Originally Posted by mkk

Perhaps the integrated memory controller on the Athlon64 line pushes the memory a little bit harder. While I haven't read any technical briefs concerning this it's something that keeps pop'ing up in various reviews. Identical RAM timings in between systems does not indicate identical memory performance, as there is much more to it than that.

this like on all amd and intel chipsets like nforce2 /3 /ktXX intel 8XX

people say intel does better in the memory area this maybe why? but why does this workthat way is what baffles me

grog · Sep 26, 2004, 03:09 AM

That is the right idea.

The speed of the RAM (DDR200/333/400) the memory controller and channel interleaving timing all play a part.

If the RAM timing is in AUTO mode then the SPD EEPROM on the RAM device is read. Next the timing of the RAM part is used to determine the timing required for that platform. The timing is based not just on the SPD EEPROM vaules but other factors including the memory controller being used. Really you can not even compare the AMD part against the Intel based on the RAM timing values shown directly, other factors play a role on fast the RAM actually is.

Should try this with Embedded systems. For example on a StrongARM or PowerPC board you would need to read in the SPD EEPROM value, take the CPU clock speed and start determine the best values to use. For the Athlon-64 the good news is the memory controller is "built-in" so values from similiar boards should be the same.

Here is the pdf design guide for the Athlon-64 BIOS from AMD.

http://www.amd.com/us-en/assets/cont...docs/26094.PDF

Greg

Quote:

Originally Posted by mkk

Perhaps the integrated memory controller on the Athlon64 line pushes the memory a little bit harder. While I haven't read any technical briefs concerning this it's something that keeps pop'ing up in various reviews. Identical RAM timings in between systems does not indicate identical memory performance, as there is much more to it than that.

Sep 26, 2004, 02:15 AM	#1
The_Neon_Cowboy HardwareHeaven Extreme Member Join Date: Dec 2002 Location: U.S.A. Posts: 16,009 Rep Power: 92 System Specs	Why do memory timeings differ from amd / intel on the same ram? Why do memory timeings differ from amd / intel on the same ram? For example I'm looking at some ram some have it has duel times listed others adverise just thier thier intel timeings... I read carefully the feed back on sites that allow it on thier sales page like newegg.... For example a stick of PDP System 512 pc 3200 mb ram AMD:2.5-3-3-8-T1 Intel:2-3-2-5-T1 Thats a big differance so much I woun't buy the ram. But a big problem they only advertise the intel speeds. Not what they will do on AMD's... Some have duel timeing listed...I don't under stand why the intels will let the ram do better timeings with the exact same stick of ram at the same speed. __________________

Sep 26, 2004, 02:32 AM	#2
drakesteakn boo!!!! Join Date: Aug 2003 Location: Ft. Meyers, FL Posts: 2,041 Rep Power: 0	i always wondered that myself. __________________

Sep 26, 2004, 02:43 AM	#3
mkk Cthulhu/Dagon 2012 Join Date: Oct 2003 Location: Gefle, Sweden Posts: 4,490 Rep Power: 132 System Specs	Perhaps the integrated memory controller on the Athlon64 line pushes the memory a little bit harder. While I haven't read any technical briefs concerning this it's something that keeps pop'ing up in various reviews. Identical RAM timings in between systems does not indicate identical memory performance, as there is much more to it than that.