After the GeForce RTX 4080 (test), Nvidia is now apparently also upgrading the gaming top model GeForce RTX 4090 (test) to a new graphics chip. Nothing changes for end customers: the basic technical key data, performance and recommended retail price remain the same.
New GPU iteration with comparator for fan control
In mid-January, the first batches of the GeForce RTX 4080 with AD103-301 graphics chip found their way onto the market, after the graphics card had previously only been equipped with the AD103-300. Nvidia had quietly started replacing the original GPU variant with a new chip. It was manufactured in TSMC's N4 process, nothing changed in the number of FP32 execution units and the clock rates remained identical, as did performance and power consumption. So why the change? At first there was a slight saving in production costs, but this suspicion could not be confirmed.
AD102-301 AD103-300
AD103-301 AD104-400 AD104 -250
AD104-251 AD106 AD107 Manufacturing TSMC N4 Chip Size 608mm² 379mm² 295mm² 190mm² 146mm² Transistors 76.3B 45.9B 35.8B ? SMs 128 76 60 46 34 24 FP32 ALUs 16384 9728 7680 5888 4352 3072 Base Clock 2230MHz 2210MHz 2310MHz 1920MHz ? Boost Clock 2520MHz 2510MHz 2610MHz 2475MHz ? FP32 computing power 82.6 TFLOPS 48.8 TFLOPS 40.1 TFLOPS 29 TFLOPS ~ 22 TFLOPS ~ 16 TFLOPS *Data not officially confirmed
A more likely explanation is that the first iteration of the AD103 graphics chip didn't have a comparator to match the PWM signal to the actual RPM reported by the cooler, according to Igor's lab based on their own analysis of various PCBs and subsequent research in industry circles had experienced. Earlier graphics cards with an AD103-300 GPU were dependent on the dedicated comparator chip “U121” on the PCB; this workaround is no longer required for GeForce RTX 4080 models with an AD103-301 chip.
The GeForce RTX 4090 also gets one new chip
The GeForce RTX 4090 and GeForce RTX 4070 Ti (test) were not affected. However, a Reddit user is now reporting a GeForce RTX 4090 Founders Edition, which is equipped with an AD102-301 instead of the AD102-300. The cause is presumably to be found again in the omission of the independent comparator chip on the PCB, but this has not yet been confirmed.
GeForce RTX 4090 FE with AD102-301-A1 (image: cavitysearch123)
In fact, u/cavitysearch123 reports a change in voltage: While the limit of the AD102-300 was 1,100 millivolts, the voltage of the AD102-301 can only be increased up to 1,070 millivolts, which is a limitation, at least on paper when overclocking; however, the change is not decisive. It is also unclear whether only Founders Editions with AD102-301 GPUs or also custom designs with the new chip are affected – so it remains to be seen here.
In any case, a BIOS flash to an old firmware version compatible with the GeForce RTX 4090 with AD102-300 GPU is not possible, notes u/cavitysearch123: Die Board IDs do not match.
CB-Funk Podcast Episode #10: “More appearances than reality” also applies far too often to hardware