Under the Heatsink

Please note that removing the heatsink from this card will void your warranty.


After popping off the ridiculous number of screws holding down the stock heatsink, we get our first glimpse of what makes this graphics card tick. The basic layout is very similar to that of the 8800GTS 512MB but there have been some massive changes made to the back end of the card in particular. Both the capacitors and the voltage regulation sections have taken a good hit of steroids and have beefed up quite a bit when compared to other G92 cards since the 9800GTX uses a 4+2 phase power module


Note to all the more inexperienced users reading this article: this is NOT what a good application of thermal compound looks like. After taking a good thirty minutes to remove the Nvidia-applied goop we were finally able to see the exposed core of the 9800GTX in all its glory. The heart of this beast is the “new” 65nm G92-420 core in its A2 revision and it should be noted this is NOT the exact same core which was used on neither the 8800GT (G92-270) nor 8800GTS 512MB (G92-400).


The memory modules used on the 9800GTX are Samsung K4J52324QE-BJ08 units set up in an 8x64MB pattern around the core. These are GDDR3 modules which are rated at a blistering 1200Mhz (2400Mhz DDR) at 0.83ns which means there should be quite a bit of overclocking headroom left as well.


At first we had thought that the green light on the backplate was a dim LED but upon closer inspection it looks like Nvidia has used fiber-optic cables to transmit the light generated by an LED on the PCB. The optical filaments are housed in black plastic sleeving so exterior light doesn’t affect their illumination in any way.

The SPDIF connector sits all by its lonesome on the PCB and unfortunately, we were not able to test whether it works with aftermarket connectors since we could not find a compatible DVI to HDMI adaptor.


The dual SLI connector is used for running three 9800GTX cards in 3-Way SLI and is a major contributing factor for the additional length of this card over the other G92-based cards.


By taking apart the cooler assembly we see that the 9800GTX uses the same 3-heatpipe heatsink as the 8800GTS 512MB. There are 3 copper heatpipes which make contact with a copper GPU contact plate before running through the aluminum fins of the main heatsink that are used to disperse the heat generated by the core.


Underneath the 80mm fan, there are black aluminum-painted columns that are used to disperse the heat from the VRM modules. Meanwhile, the copper base is quite flat but is definitely not polished to a mirror finish which would be quite pointless considering the amount of thermal compound Nvidia applies.