R600 memory not running at full speed?

Hello everyone,

I've recently bought a used R600-10Q which is the most basic model with SU9300/1.2Ghz and no WWAN.
I'm very happy with my purchase but I've noticed that the memory is only running at 667Mhz instead of the advertised 800Mhz.
I can confirm this by running Memtest, CPU z and various other hardware monitoring software.

Here's what I have tried so far:
- Updated BIOS to most recent version
- Removing the additional 2Gb stick so it's only running of the memory which is soldered to the mainboard
- Setting CPU speed to full power in BIOS with High performance profile setting in Vista
- Setting CPU speed to dynamically in BIOS
- Doing memory and cpu stress tests with various software
- Trying Vista 32bit and Vista 64bit
- Trying different monitoring software

All of this didn't help. Do you guys have any other ideas?
CPU Z (and other software) detected the RAM as PC6400 but running at PC5300 speed.

Can anybody with a R600 run CPU Z and confirm theirs is running at 800Mhz?

 

Is there any memory speed option in the BIOS? It could be under the power management: Slower RAM speed saves a little power.

In reality, if your RAM is running at 667MHz with a latency of CL=4 then the loss in throughput is quite small compared to 800MHz running at CL=5.

John

 

Hi John,

Thanks for your quick reply.
No, there are no further memory speed settings in the BIOS.
I even installed other BIOS revisions to see if they contained any further settings but they're all the same.
My memory is running at 667Mhz with 6-5-5-15 timings.
I don't even know why it is running with 6-5-5-15 instead of 5-5-5-15 at 667Mhz.

But all of this doesn't really matter because it clearly should be running at 800Mhz with 6-6-6-18 timings!

I've also installed the latest version of Everest Ultimate and still showing as 667Mhz.
This is pretty weird since the memory is soldered to the mainboard and comes directly from Toshiba so there shouldn't be any incompatibilities or lower than advertised speed.
The R600-10Q is already the most basic model so I need all the speed I can get and 800Mhz would mean that the ram/fsb ratio is 2:1 synchronous which would give it even more speed than the 5:3 asynchronous ratio right now.

 

I've received my unit back from warranty repair today.
They said that the memory should only be running at 667Mhz even though it is PC6400/800MHz rated.

I don't really believe Toshiba to be honest.
Why would they install PC6400 memory in their machines only to be running it at PC5300 speed?
That doesn't make any sense!

Please, can anybody with a R600 please confirm their memory speed and post it here!!!

 

There is some sense behind this. Slower RAM uses less power and the chipset can't use the whole bandwidth of PC-6400 RAM.

Run SiSoftware Sandra's memory bandwidth benchmark and see how the speed compares with PC6400 RAM using the same chipset.

John

 

Hm, I didn't think about battery life being a factor but you could be right.
As far as speed goes there shouldn't be a noticeable difference in real world performance.

Thanks for your reply again John