Thursday, June 6th 2024
Hands On with the Only Radeon RX 7900 XTX Model that has 12V-2x6 Power Connector
At Computex 2024, we went hands-on with the only custom-design AMD Radeon RX 7900 XTX graphics card to implement the 16-pin 12V-2x6 power connector. We've written quite a bit about this card, but weren't expecting it to be this long. This isn't just the only RX 7900 XTX with a 12V-2x6, but also the only air-cooled RX 7900 XTX that's strictly 2 slots-thick. ASRock made this card for graphics rendering farms, or AI development/inferencing builds, in which a GPU server would have 4-6 of these packed like sardines. The lateral blower helps ensure proper ventilation. The backplate is recessed to ensure better ventilation to the neighboring card.
The card sticks to AMD reference clock speeds of 2270 MHz Game clock, and 20 Gbps (GDDR6-effective) memory speed. ASRock also gave us a technical deep-dive into the card's design. For one, it's confirmed that the power connector is 12V-2x6 (H++) and not 12VHPWR. The cooling solution consists of a large copper vapor-chamber plate that makes contact with the GPU, memory, and VRM; conveying heat to an aluminium channel heatsink, which is ventilated by a high-speed lateral blower. The cooler shroud and backplate are both made of aluminium.
The card sticks to AMD reference clock speeds of 2270 MHz Game clock, and 20 Gbps (GDDR6-effective) memory speed. ASRock also gave us a technical deep-dive into the card's design. For one, it's confirmed that the power connector is 12V-2x6 (H++) and not 12VHPWR. The cooling solution consists of a large copper vapor-chamber plate that makes contact with the GPU, memory, and VRM; conveying heat to an aluminium channel heatsink, which is ventilated by a high-speed lateral blower. The cooler shroud and backplate are both made of aluminium.
27 Comments on Hands On with the Only Radeon RX 7900 XTX Model that has 12V-2x6 Power Connector
I dont understand why such designs and form factors were abandoned.
The current 4 slots monstrosities are a plague.
Curious decision to have the backplate cover only have the card, it's stated as to ensure better ventilation to the neighboring card, which is understandable, but I'd wager is unlikely.
The reason they are inefficient is because the heat path is long. The heat generated in the first portion is transferred to the air, which then cools a later portion, which brings more heat into that air, which then cools a later portion. So on and so forth. It's a cascade of heat and inefficiency. By the end, there is a lot of heat in a small volume of air, and little capacity for that air to absorb more heat (little difference in temperature delta). To overcome this problem, a very high velocity of air is required.
Axial coolers are much more efficient because each air path is very short. They transfer heat to the air, and then the air goes away. The biggest drawback is that the heat all goes into the case, but since a case is big with big sides, you can generate a relatively high volume of air being replaced in the case without making a lot of noise.
If you think current axial coolers are monstrosities, imagine how monstrous a less efficient blower cooler would need to be in order to provide similar cooling and usability in a home setting.
Why anyone would deliberately switch from the legacy 8-pin PCIe power connectors to this ridiculous abortion 12VHPWR connector is a mystery. The only conclusion one can reasonably reach is that they are idiots. Being the 12V-2x6 (H++) variant of the same underlying trash design doesn't make it OK.