Motherboard does not see 1066mhz only 800 why

[tegralens]

I have a GA-MA78GM-US2H with a amd athlon x2 7850 BE with corsair xms2 twin 2x 4gb pc8500 ddr2 For some reason the mother does not recognize the 1066mhz it can only see 800mhz can anyone help with this.

 

[bilbat]

Have you done a "Load Optimized Defaults" from the BIOS? The function forces the BIOS to run a block of 'discovery' code that 'reads' the hardware (especially the SPD/EPP on the RAM) and sets the myriad 'auto' parameters in the CMOS to accomodate what it finds...

 

[mindless728]

pC2-8500 isn't in the jedec specifications and AMD doesn't use extended profiles (like XMP)
you have to manually set the voltage, timings, and speed in the bios

 

[bilbat]

First of all, JEDEC DDR2-8500 (1066) specification is here:
http://www.mediafire.com/?yjemzotwuo2
I keep about a half-gig of JEDEC specs here, on everything from "STANDARD METHOD FOR CALCULATING THE ELECTROMIGRATION MODEL PARAMETERS FOR CURRENT DENSITY AND TEMPERATURE", to "DRIVER SPECIFICATIONS FOR 1.8 V POWER SUPPLY POINT-TO-POINT DRIVERS", to "GDDR4 Specific SGRAM Functions" - often come in very handy!

I don't have a lot of experience with AMDs, but I'm game if you are

On the "MB Intelligent Tweaker(M.I.T.)" page:

"Set Memory Clock" to "Manual"
If "Memory Clock" item is currently at "X4.00", set it to "X5.33", otherwise post back its current setting...

"System Voltage Control" to "Manual"
"DDR2 Voltage Control" to "+0.3V"

On the "Advanced BIOS Features" page, you may need to test with the "AMD K8 Cool&Quiet control" item both at "Auto" and at "Disabled"; I suspect it may behave like the Intel 'green features', and adversely affect stability if enabled, but, as I said - don't really know...

I believe that at 1066, you will be permanently limited to 2 DIMMs, but I think that should do it!

Good luck!

Bill

 

[tegralens]

Have you done a "Load Optimized Defaults" from the BIOS? The function forces the BIOS to run a block of 'discovery' code that 'reads' the hardware (especially the SPD/EPP on the RAM) and sets the myriad 'auto' parameters in the CMOS to accomodate what it finds...

Did not work

 

[tegralens]

First of all, JEDEC DDR2-8500 (1066) specification is here:
http://www.mediafire.com/?yjemzotwuo2
I keep about a half-gig of JEDEC specs here, on everything from "STANDARD METHOD FOR CALCULATING THE ELECTROMIGRATION MODEL PARAMETERS FOR CURRENT DENSITY AND TEMPERATURE", to "DRIVER SPECIFICATIONS FOR 1.8 V POWER SUPPLY POINT-TO-POINT DRIVERS", to "GDDR4 Specific SGRAM Functions" - often come in very handy!

I don't have a lot of experience with AMDs, but I'm game if you are

On the "MB Intelligent Tweaker(M.I.T.)" page:

"Set Memory Clock" to "Manual"
If "Memory Clock" item is currently at "X4.00", set it to "X5.33", otherwise post back its current setting...

"System Voltage Control" to "Manual"
"DDR2 Voltage Control" to "+0.3V"

On the "Advanced BIOS Features" page, you may need to test with the "AMD K8 Cool&Quiet control" item both at "Auto" and at "Disabled"; I suspect it may behave like the Intel 'green features', and adversely affect stability if enabled, but, as I said - don't really know...

I believe that at 1066, you will be permanently limited to 2 DIMMs, but I think that should do it!

Good luck!

Bill

This worked pretty much but I set the Voltage to +.2V instead just to be safe. Now I have to see if it is stable.

 

[bilbat]

This worked pretty much but I set the Voltage to +.2V instead just to be safe. Now I have to see if it is stable.

You have absolutely the right idea there... 'Optimal' is basically however fast you want it to run, at the lowest voltage you can manage it! All DDR2 is, at its heart, DDR2-800 whose JEDEC spec voltage is 1.8V (so when the BIOS lists '+0.1V', that's 1.8 +0.1, meaning our '+0.3' is the RAM's rated 2.1) - to get faster speeds, the manufacturers specify a higher voltage (in the case of your RAM, 2.1V) which guarantees it will at least reach that higher speed - but - (to quote George and Ira Gershwin) "it ain't necessarily so!"; some of it will run plenty fast at a lower voltage, and to do so is a good thing! The dev system I'm sitting at has 8G of 2.1V G.Skill 1066 running at 1080, and, for the first six or eight months of use, I had it at 2.0V, a tenth volt low. Then, gradually, it developed some 'fringe' instability when I really pushed it, so I bumped the RAM up half a tenth (to 2.05V) and it stabilized perfectly - still below the manufacturer's specified voltage...

If she's stable, definitely leave it at 2.0 (+0.2V); if not, first try (assuming your BIOS will let you) bumping it up a half-tenth to +0.25 - might be happy there!

 

[tegralens]

Thanks for everyone's help.

 

[Victek]

I have a GA-MA78GM-US2H with a amd athlon x2 7850 BE with corsair xms2 twin 2x 4gb pc8500 ddr2 For some reason the mother does not recognize the 1066mhz it can only see 800mhz can anyone help with this.

.
Now that you have it running at 1066 is there any measurable or noticeable difference in performance? I ask because my Gigabyte motherboard is doing exactly the same thing (running my 1066 rated ram at 800 mhz with auto settings) and I wonder if it makes much difference?

 

[tegralens]

Well I am waiting until I get my Windows 7 64 bit to try it out. But I did up the voltage to +0.3V so I can get 2.1 volts because the memory should be at 2.1 that is that the manufacture recommends. But I will know after I get my Windows 7 because I brought 4 more Gigs so I will be running 8gb.

 

[Mongox]

Victek and tegralens,

If the RAM is set to 1066 at its proper timing settings and compared to 800 at its proper settings, the speed difference isn't usually much. But you're running the RAM properly, with the proper voltage and settings and it's more stable. Remember, all BIOS don't read the SPD perfectly - and they never 'read' the voltage. Certainly not on AMD systems.

Once you have it working "right", you can fiddle around and see what you can do to tweak it. You might prefer running your 1066 @ 6 at the lower speed and faster timing of 800 @ 5. This isn't overclocking, just taking advantage of what's offered you. However, you might be able to run it at 800 @ 4, like I do mine and really get some nicer results - which would be overclocking.

Regardless, changes like these are dwarfed by minor changes in overclocking a CPU. A 5% increase in your CPU speed translates as almost 5% faster in all operations. So getting your RAM to run well is nice, but not a really big deal in the scheme of things.

 

[Victek]

Victek and tegralens,

If the RAM is set to 1066 at its proper timing settings and compared to 800 at its proper settings, the speed difference isn't usually much. But you're running the RAM properly, with the proper voltage and settings and it's more stable. Remember, all BIOS don't read the SPD perfectly - and they never 'read' the voltage. Certainly not on AMD systems.

Once you have it working "right", you can fiddle around and see what you can do to tweak it. You might prefer running your 1066 @ 6 at the lower speed and faster timing of 800 @ 5. This isn't overclocking, just taking advantage of what's offered you. However, you might be able to run it at 800 @ 4, like I do mine and really get some nicer results - which would be overclocking.

Regardless, changes like these are dwarfed by minor changes in overclocking a CPU. A 5% increase in your CPU speed translates as almost 5% faster in all operations. So getting your RAM to run well is nice, but not a really big deal in the scheme of things.

.
Thanks for the explanation - confirms what I was feeling about it.