felinusz
07-30-05, 10:43 PM
I have an X700 Pro equipped with Samsung GC20 memory.
My video card is both VDD and VDDQ voltage modified, both VDDR voltages are adjusteable. My card's reference memory voltages are 2.1V/2.1V - at these voltages and with RAMSinks/airflow I can bench the card at ~550 MHz without locking or crashing (light artifacting).
With a VDDQ overvolt to 2.25V, and a VDD overvolt to 2.2V, the card can bench at 555 MHz (not quite "nothing", but quite close). Moving VDD and VDDQ around (running VDD hotter than VDDQ, both running them the same), within a 2.25V range, accomplishes absolutely nothing.
I have a suspicion that ATi's memoy timings are either too tight, or optimized in a peculiar manner - I intend to take a look at a few nVidia BIOSes and see if adjustment of my timings will take this memory further.
But, bad timings do not account for the terrible scaling with voltage. Overvoltage seems to accomplish next to nothing - a 5 MHz gain for ~.15V is terrible.
The chips have large copper heatsinks epoxied on with ASA epoxy.
Am I doing something wrong, or is Samsung GC20 always this poor a performer?
My video card is both VDD and VDDQ voltage modified, both VDDR voltages are adjusteable. My card's reference memory voltages are 2.1V/2.1V - at these voltages and with RAMSinks/airflow I can bench the card at ~550 MHz without locking or crashing (light artifacting).
With a VDDQ overvolt to 2.25V, and a VDD overvolt to 2.2V, the card can bench at 555 MHz (not quite "nothing", but quite close). Moving VDD and VDDQ around (running VDD hotter than VDDQ, both running them the same), within a 2.25V range, accomplishes absolutely nothing.
I have a suspicion that ATi's memoy timings are either too tight, or optimized in a peculiar manner - I intend to take a look at a few nVidia BIOSes and see if adjustment of my timings will take this memory further.
But, bad timings do not account for the terrible scaling with voltage. Overvoltage seems to accomplish next to nothing - a 5 MHz gain for ~.15V is terrible.
The chips have large copper heatsinks epoxied on with ASA epoxy.
Am I doing something wrong, or is Samsung GC20 always this poor a performer?