AMD's Liquid-Cooled Radeon RX 6900 XT Arrives Flexing High Clocks

Sapphire Radeon RX 6900 XT LC
Sapphire Radeon RX 6900 XT LC (Image credit: Kabum)

AMD's liquid-cooled Radeon RX 6900 XT appears to be making its way to the retail market. VideoCardz has spotted a Sapphire listing over at a Kabum, a Brazilian retailer.

Speculation around the graphics card world is that the Radeon RX 6900 XT LC could very well be the incarnation of the rumored Radeon RX 6900 XTX. The latter was expected utilize the Navi 21 XTXH silicon, which allegedly brings the highest clock rates out of AMD's RDNA 2 army. Although we've already seen the graphics card in the wild, AMD hasn't formally confirmed the existence of the Radeon RX 6900 XT LC.

The Sapphire Radeon RX 6900 XT LC, which should employ the Navi 21 XTXH die, comes with 80 Compute Units (CUs) for a total of 5,120 Stream Processors (SPs). Along with those 5,120 SPs, you'll also find 80 ray accelerators for ray tracing workloads. The Radeon RX 6900 XT LC arrives with a 2,250 MHz game clock and a boost clock up to 2,435 MHz. The vanilla Radeon RX 6900 XT has a 2,015 MHz game clock and 2,250 MHz boost clock. Therefore, Sapphire's rendition is offering up to 11.7% and 8.2% higher game and boost clocks, respectively.

Besides the uplift in clock speeds, Kabum's specification table also shows an increase in memory speed for the Radeon RX 6900 XT LC. Apparently, the liquid-cooled version sports 18 Gbps GDDR6 memory chips as opposed to the 16 Gbps ones on the Radeon RX 6900 XT. It may be a human error, but it's certainly feasible, considering that Samsung produces 18 Gbps GDDR6 memory chips. If accurate, the extra frequency on the memory chips bumps the Radeon RX 6900 XT LC's maximum theoretical memory bandwidth up to 576 GBps, a 12.5% improvement over the regular version.

AMD Radeon RX 6900 XT LC Specifications

Swipe to scroll horizontally
Header Cell - Column 0 Radeon RX 6900 XT LC*Radeon RX 6900 XT
Architecture (GPU)RDNA 2 (Navi 21)RDNA 2 (Navi 21)
CUDA Cores / SP5,1205,120
RT Cores8080
Ray Accelerators8080
Texture Units320320
Base Clock Rate?1,825 MHz
Game Clock Rates2,250 MHz2,015 MHz
Boost Clock Rate2,435 MHz2,250 MHz
Memory Capacity16GB GDDR616GB GDDR6
Memory Speed18 Gbps16 Gbps
Memory Bus256-bit256-bit
Memory Bandwidth576 Gbps512 GBps
ROPs128128
L2 Cache4MB4MB
L3 Cache128MB128MB
TDP?300W
Transistor Count26.8 billion26.8 billion
Die Size536 mm²536 mm²
MSRP?$999

*Specifications are unconfirmed.

The Sapphire-branded Radeon RX 6900 XT LC (21308-02-10G) shares the same design as the Radeon RX 6900 XT LC that recently popped up inside a gaming PC over in China. Although listed as a Sapphire SKU, there are no signs of the Sapphire logo or any type of third-party marketing on the graphics card itself.

It stands to reason that the Radeon RX 6900 XT LC likely conforms to an AMD reference design where the chipmaker's partners are free to slap their name beside the Big Navi graphics card. It flaunts a dual-slot design with aluminium plates on both sides of the graphics card. For comparison, the Radeon RX 6900 XT reference edition conforms to a 2.5-slot design. Evidently, there are no cooling fans so the Radeon RX 6900 XT LC's only method of staying cool is the included 120mm AIO liquid cooler.

Despite coming with a significant factory overclock, the Sapphire Radeon RX 6900 XT LC still uses a pair of 8-pin PCIe power connectors. It's uncertain if the liquid-cooled variant still abides by the 300W TDP (thermal design power) limit as the normal Radeon RX 6900 XT, though. One would expect a more generous TDP, given the higher clock speeds on the Radeon RX 6900 XT LC.

The display outputs on the Sapphire Radeon RX 6900 XT LC, on the other hand, remains unchanged. Like AMD's reference design, the liquid-cooled variant retains support for four monitors. It offers the standard HDMI 2.1 port, two DisplayPort 1.4 outputs and one USB Type-C port.

Kabum has the Sapphire Radeon RX 6900 XT LC up for preorder at $4,662.40 or $3,368.41 in a single cash payment. Don't pay attention to the pricing since it probably includes VAT (value-added tax) and a huge retailer markup. Kabum claims that it'll start shipping Sapphire Radeon RX 6900 XT LC orders on June 30 so we could see an announcement from AMD very soon.

Zhiye Liu
RAM Reviewer and News Editor

Zhiye Liu is a Freelance News Writer at Tom’s Hardware US. Although he loves everything that’s hardware, he has a soft spot for CPUs, GPUs, and RAM.

  • Phaaze88
    Oh, a continuation of the other thread.

    A fan on the actual card would've been nice...
    Reply
  • VTXcnME
    And none the new card abilities actually matters, as none of these cards (as is the pattern of the last year or so) will get into the hands of actual gamers/users

    But boy... I bet it'll mine crypto nicely. :rolleyes:

    Going forward, all the articles about new cards ought just be directed at how well they crypto mine... those are the only users getting their hands on any cards.
    Reply
  • usiname
    I don't know what is more annoying, the prices of the GPUs, or this spam in every article in every second post complaining for everything. I think the second, but they still think they are funny and wont stop complaining.
    Reply
  • Sleepy_Hollowed
    Hopefully it’s quieter than a triple fan design. I have a triple fan card that has no fan spin unless you’re playing games (it lowers clocks to achieve this), and going full blast the fans never go above 1200 rpm so I’m super spoiled in that front.
    Reply
  • -Fran-
    What the hell? A single 120mm rad design for 300W? I thought this was going to be a hybrid card, but that design does not give me any confidence it'll be sufficiently cooled... Unless it has a hidden fan somewhere for the HSF or some other dark arts are at play here.

    So weird... And potentially a bad idea!

    I hope someone reviews this, because it's interesting, to say the least.

    Regards.
    Reply
  • usiname
    Yuka said:
    What the hell? A single 120mm rad design for 300W? I thought this was going to be a hybrid card, but that design does not give me any confidence it'll be sufficiently cooled... Unless it has a hidden fan somewhere for the HSF or some other dark arts are at play here.

    So weird... And potentially a bad idea!

    I hope someone reviews this, because it's interesting, to say the least.

    Regards.
    Fury X is 275W with 120mm rad and is very well cooled
    Reply
  • -Fran-
    usiname said:
    Fury X is 275W with 120mm rad and is very well cooled
    That was the high limit, yes. These cards hit 300W normally, so it's 25W extra power which is not trivial and this is a smaller area with a lot more heat on surfice (denser than Fury).

    As I said, this is interesting and I'd like to see it tested. I'm curious if this actually can handle 300W without a hybrid design.

    Regards.
    Reply
  • Phaaze88
    I was expecting a fan on it too...


    Fury X appears to be 300w.
    6900XT also appears to be 300w. Heck, the Strix LC and Sapphire Toxic are both 289w?
    Reply
  • -Fran-
    Phaaze88 said:
    I was expecting a fan on it too...


    Fury X appears to be 300w.
    6900XT also appears to be 300w. Heck, the Strix LC and Sapphire Toxic are both 289w?
    It has a board power limit of 300W and a temp cap of 75°C due to HBM. But fair; let's say both cap at 300W.

    And the aftermarket models of the 6900XT are hybrids with a fan, so not quite the same as this one.

    Regards.
    Reply
  • usiname
    Yuka said:
    That was the high limit, yes. These cards hit 300W normally, so it's 25W extra power which is not trivial and this is a smaller area with a lot more heat on surfice (denser than Fury).

    As I said, this is interesting and I'd like to see it tested. I'm curious if this actually can handle 300W without a hybrid design.

    Regards.
    Fury X is 596 mm²
    6900 xt is 520 mm²
    Maybe little hotter, but Fury X is 60C and even if they didn't improve the cooler it won't pass 68-70
    Reply