AMD's Radeon RX 6900 XT LC Takes RDNA2 to the Max

[harlan4096]

Navi 21 with all the bells and whistles.

German site PCGamesHardware managed to lay their hands on AMD's Radeon RX 6900 XT Liquid Cooled graphics cards that is exclusively available from select system builders and will not be sold in retail. The card features slightly higher clocks than originally advertised and therefore its performance is a bit higher than one might think. But is it radically higher? 

When AMD formally introduced its Radeon RX 6900 XT Liquid Cooled graphics card last month, it did not reveal all of its specifications. As PCGH discovered, the Radeon RX 6900 XT LC is based on AMD's Navi 21 XTXH silicon with 5120 stream processors, higher TGP (Typical Graphics Power, for the entire board), as well as no clock limitations. This means the card can be pushed to a 400W TGP, opening doors to extreme frequencies.  

By default, the GPU features a game clock of 2250 MHz, but it can boost to 2435 MHz (with a 400W TGP, it will spend more time working in boost mode than a regular Radeon RX 6900 XT board) and has some additional overclocking potential, just like other Navi 21 XTXH-powered cards.  

In addition to the higher TGP and GPU clocks, the Radeon RX 6900 XT Liquid Cooled also carries 16GB of GDDR6 memory featuring an 18.5 GT/s data transfer rate, 0.5 Gbps higher than advertised initially. That gives it 591 GB/s peak bandwidth, a 15.6% increase over the regular Radeon RX 6900 XT's 16 GT/s GDDR6 and 512 GB/s bandwidth.

With a 12% higher GPU clock and a 15.6% higher peak memory bandwidth, the Radeon RX 6900 XT Liquid Cooled is clearly faster than AMD's reference Radeon RX 6900 XT, though it still might be challenged by boards like Sapphire's Toxic Radeon RX 6900 XT Extreme Edition. But can it beat Nvidia's GeForce RTX 3090/3080 Ti in cases when the original model cannot? 

PCGH found that while there are numerous cases where AMD's limited edition Radeon RX 6900 XT LC can beat the GeForce RTX 3090/3080 Ti where an air-cooled Radeon RX 6900 XT cannot, in most cases where Nvidia's Ampere architecture excels relative to AMD's RDNA 2 (i.e., with ray tracing enabled), high clocks are not going to help. 

But while AMD's Radeon RX 6900 XT Liquid Cooled is not the fastest graphics card on the planet, it is clearly among the best graphics cards available today and the fastest RDNA2-powered product available. The board is only sold as part of high-end systems from boutique PC makers, so those who want to get an exclusive RDNA 2 card should look at Navi 21 XTXH-based offerings from Asus, ASRock, Gigabyte, Sapphire, PowerColor that do not have fast memory, but seem to have cooling systems with higher potential and therefore could offer higher GPU clocks.
...

Continue Reading