Review of the AMD Radeon RX 7900 XTX and XT: the XTX beats the Nvidia RTX 4080 for $200 less, except in power efficiency and ray tracing, and the XT comes close 中古筆電收購

中古筆電收購d changes.

The most significant is a new chiplet-based approach, similar in concept to the one AMD uses for its Ryzen CPUs. Rather than building the entire GPU die on one manufacturing process—increasing the die’s size and therefore the chances that some or all of it could be defective—AMD is building the main Navi 3 GPU die on a 5 nm TSMC manufacturing process and a series of smaller memory controller dies (MCDs) on a 6 nm process. These chips are all linked together with a high-speed interconnect, which AMD says can transfer data at speeds of up to 5.3 terabytes per second.
The main graphics compute die (GCD) contains most of the hardware you think of when you think of a GPU—compute units, shaders, ray-tracing hardware, the media encoding and decoding block, and display output. Both the 7900 XTX and XT use the same Navi 31 GCD, but the XTX runs at higher clocks and has more CUs and stream processors enabled. The XTX has 96 CUs and 6,144 stream processors, while the XT has 84 CUs and 5,376 stream processors. Both cards represent a jump up from the Navi 21 die used in the RX 6900 series, which maxed out at 80 CUs and 5,120 stream processors (and that’s before you account for other performance-boosting improvements).

RDNA 3 brings a little more of everything to AMD’s top-tier GPUs, from CU counts to memory bandwidth.

Credit:
AMD

RDNA 3 brings a little more of everything to AMD’s top-tier GPUs, from CU counts to memory bandwidth.

Credit:

AMD

The MCDs all include a single 64-bit memory controller and 16MB of AMD’s Infinity Cache, and they demonstrate the advantages of a chiplet-based approach. The 7900 XTX has a 384-bit-wide memory bus and 96MB of Infinity Cache, where the 7900 XT has a 320-bit bus and 80MB of cache; to accomplish this, all AMD has to do is remove an MCD. The exact same MCDs can be reused up and down the stack with all of the different RDNA 3 GCDs that AMD chooses to release, from low-end products with a single MCD up to midrange GPUs that use between two and four. Defects in MCD dies won’t require the larger, more complex GCDs to be thrown out or binned, and vice-versa.

In the realm of all-new features for RDNA 3, there are three things of note. First, the GPUs include new AI accelerators, which could be useful both for the plethora of AI-assisted content creation that has sprung up in the last year and for AI-assisted upscaling (if AMD chooses to implement it in some future version of its FSR upscaling algorithm; both DLSS and XeSS use AI for upscaling, but FSR 2.0 doesn’t).
Second, the video encoding and decoding block supports hardware-accelerated encoding for the AV1 video codec, just like the RTX 4000 series and Intel’s Arc GPUs. This should be useful for both content creators and streamers who want to stream higher-resolution video or video at the same resolution while using less bandwidth.
And third, the “Radiance Display Engine” adds DisplayPort 2.1 support to the GPUs. Monitors that take full advantage of DisplayPort 2.1’s extra bandwidth don’t really exist as of this writing, but when they do, RDNA 3 GPUs will be able to drive 4K displays at up to 480 Hz and 8K displays at up to 165 Hz.

The actual GPUs

AMD is using the physical size of the 7900 series, in light of the huge 4000-series GPUs.

AMD is using the physical size of these new GPUs as a selling point, as well as the fact that they use typical 8-pin power connectors (there have been jokes). We’ve only seen the first-party cards AMD is making and selling itself, but if their partners follow their lead, these GPUs will be notable for looking like a run-of-the-mill 2.5-slot GPU. Unlike the RTX 4090 and 4080, they’re not so huge that you’ll need to worry about whether they’ll fit in your case, and you won’t need to learn the ins and outs of a new power connector.
Like some of the 6000-series cards, the 7900 series is somewhat odd in that it includes a USB-C port instead of a third DisplayPort; a USB-C-to-DisplayPort or USB-C-to-HDMI adapter or cable will let you use it like you would a regular display output, but for the (still rare-ish) gaming monitors with USB hubs and USB-C ports, it can handle display output and USB data over one cable. The Gigabyte M28U I use does meet these criteria, so I appreciate the addition; for people who need three DisplayPorts, it means another adapter or a cable with different connectors at both ends.

The 2.5-slot 7900 series is still thicker than 2-slot cards like the Radeon RX 6800 (top).

Credit:
Andrew Cunningham

The 2.5-slot 7900 series is still thicker than 2-slot cards like the Radeon RX 6800 (top).

Credit:

Andrew Cunningham

The 7900 XTX is, by a very small amount, the larger of these two cards, though they’re in the same ballpark. The XTX is also the only one of the two with any kind of LED lighting—some relatively low-key white strips on the fan-side of the card, similar to what Nvidia is doing with the RTX 4090 and 4080. The XT does away with LED lighting altogether. If this is the kind of thing you’ll like, you’ll need to look at partner cards to see whose gigantic rainbow lights can brighten your case the most.
Game performance

Gaming testbed

CPU
AMD Ryzen 7 5800X3D (provided by AMD)

Motherboard
Asus ROG Crosshair VIII Dark Hero (provided by ASUS)

RAM
64GB DDR4-3200 (provided by Crucial)

SSD
Western Digital Black SN850 1TB (provided by Western Digital)

Power supply
EVGA Supernova 850 P6 (provided by EVGA)

CPU cooler
280 mm Corsair iCure H115i Elite Capellix AIO

Case
Lian Li O11 Air Mini

We don’t have a 6900 XT or 6950 XT to test against, so we’ll focus mostly on comparisons to Nvidia’s products (we have provided AMD’s own numbers for reference). The RTX 4080 is the most important comparison—it’s what the 7900 series has been priced in response to, and it’s the cheapest next-generation GPU Nvidia has on the market while we wait on the rebranded 12GB RTX 4080 to come out.
But we’ve also tested it against Nvidia’s RTX 3080 Ti, which is still being sold new for as much or more than AMD is asking for the 7900 series cards. Used and refurbished RTX 3080 Tis offer a better value, of course, but they come with the standard caveats: You don’t know where a used GPU has been, you have to be careful not to get scammed, and you usually don’t have a warranty to fall back on if something goes wrong.

Credit:
Andrew Cunningham

Credit:

Andrew Cunningham

We don’t spend a ton of time poring over synthetic benchmarks in GPU reviews, because their results aren’t always borne out in real-world games. But in this case, the results do capture the RX 7900 XTX and XT’s performance in a microcosm. The XTX is faster than the 4080 in the DirectX12-based Time Spy test and DirectX11-based Fire Strike test, while the XT runs a bit behind the 4080. But the 4080 does better in any test that touches ray-tracing, including the Port Royal benchmark and the ray-tracing-specific test. Both cards outrun the 3080 Ti in most tests, but it’s closer in the ray-tracing-enabled benchmarks.

Results with an asterisk were collected using a different test PC. Results should be comparable, overall.

Andrew Cunningham

Results with an asterisk were collected using a different test PC. Results should be comparable, overall.

Andrew Cunningham

AMD’s testing data comparing the RX 7900 XTX and XT to the 6950 XT.

AMD

Both cards acquit themselves well in actual games, too. In titles with no ray-tracing features included or enabled, there’s not a single one of our tests where the RTX 4080 can beat the RX 7900 XTX. The 7900 XT is usually behind the RTX 4080, but it generally keeps it close.
It’s true that AMD’s best card can’t catch up to the RTX 4090, which beats it across the board (and sometimes by a lot). If you’re solely focused on “performance crown”-type bragging rights, Nvidia is still the way to go. But that card is also $500 more expensive, so there’s absolutely no question which GPU offers the better value for the money.
So far, so good for the RX 7900 cards. But things get more complicated when you start tracing rays.

Hit-and-miss ray-tracing
Ray-tracing performance was one of the RX 6000 series’ biggest downsides. The situation does improve with the 7900 series, insofar as more ray-traced games will be playable on these cards than were playable on 6900-series GPUs. But there’s still a notable performance gap between both 7900 GPUs and the 4080. There are still some games, both in our tests and in AMD’s reference scores, where the 7900 XTX can score small wins. But the consistent wins for the 7900 XTX and near-misses from the 7900 XT that we’ve seen in other games don’t really materialize here.

Andrew Cunningham

AMD’s own numbers show similar results to ours: it’s not impossible for the RX 7900 XTX to beat the RTX 4080 in games with ray-tracing enabled, but those results are the exception and not the norm.

Both 7900 cards can handle ray-tracing at 4K reasonably well, especially in games where it’s used more sparingly (the sun-drenched glassy locales in Hitman 3 tax the card more than brakelight effects in Forza 5 or torches in Tomb Raider do). But in Quake II RTX and Hitman 3, the cards both struggle at 4K, and FSR 2.0 at its highest-quality setting doesn’t help the Radeon cards as much as DLSS can help Nvidia’s; the 7900 XTX performs a bit more like the 3080 Ti, not the 4080, in these ray-traced games.
The 1 percent low scores from Hitman are telling—the RTX 4080 with DLSS is twice as fast here as the RX 7900 XTX with FSR 2.0, which means that the game feels playable throughout on the RTX 4080, while the Radeon cards still struggle with choppiness.

This isn’t a disaster for AMD. Some of the games we tested ran quite well at 4K, and more challenging games like Hitman and Quake II RTX run pretty well if you step down to 1440p (or use a high-performance FSR setting, instead of the high-quality setting we default to for testing). But it does complicate the narrative a bit. The 7900 XTX and XT are good 4K graphics cards unless you need consistently great ray-tracing performance, in which case Nvidia still provides the better experience.
Good and bad news on power efficiency

The RX 7900 series still uses 8-pin power connectors, the same as older GPUs.

Credit:
Andrew Cunningham

The RX 7900 series still uses 8-pin power connectors, the same as older GPUs.

Credit:

Andrew Cunningham

AMD rates the 7900 XTX’s total board power at 355 W and the 7900 XT’s at 315 W (up from the 300 W it was originally announced at). The RTX 4080’s total board power is listed at 320 W, and the 3080 Ti’s is 350 W.
We measured average GPU power draw while running the Hitman 3 and Borderlands 3 benchmarks, just to get a basic sense of each card’s power efficiency.
There’s good and bad news for AMD here. On the bad side, the RTX 4080 is the more efficient card, especially in games with ray-tracing effects enabled—its average power consumption also came in quite a bit under the rated 320 W. The 7900 XT consumes a little more power to provide slightly worse performance in Borderlands 3, and the Hitman comparison is particularly unflattering.

Credit:
Andrew Cunningham

Credit:

Andrew Cunningham

The good news is that the 7900 XTX at least manages to provide better performance in exchange for its power use, as long as ray-tracing isn’t involved. And both cards are a major improvement over the power efficiency of the RTX 3080 Ti in non-ray-traced games, providing better performance in Borderlands 3 at similar power levels (for the XTX) and much lower power levels (for the XT). For most people, these cards should represent an efficiency upgrade even if they can’t quite catch Nvidia’s.
The smaller cooling systems on these cards plus the higher power consumption do mean that these Radeon cards run a bit hotter than the RTX 4080. While HWInfo measured its average temperature at 57.6 degrees during the Hitman test and 56.1 during the Borderlands 3 test, the 7900 XTX averaged 70 degrees in both tests, and the 7900 XT was 66.4 and 64.6 degrees, respectively. These aren’t dangerous temperatures, but especially in the XTX’s case, I could feel that extra heat being vented out of my case during extended gaming and benchmarking sessions.

Status quo

Xbox Series S for scale. The 7900 XTX is smaller than the 4080, but that doesn’t make it tiny.

Credit:
Andrew Cunningham

Xbox Series S for scale. The 7900 XTX is smaller than the 4080, but that doesn’t make it tiny.

Credit:

Andrew Cunningham

The Radeon RX 7900 XTX and XT don’t alter the balance of power in the GPU business. As has been the case for years, Nvidia has the edge in power efficiency, high-end performance, and add-on features like DLSS, while AMD gets by with pretty good cards that emphasize raw rasterized gaming performance for the money. At $899 and $999, these are a far cry from the RX 480 and RX 580 days a few years ago, but the dynamic is the same—AMD has undercut the RTX 4080 on price while staying within spitting distance on performance in most non-ray-tracing games (the 7900 XTX usually beats the 4080 in games

中古筆電收購全國電子啟動開學季促銷。（圖／全國電子提供）

全國電子啟動開學季活動，瞄準時下正夯的AI PC話題，和宏碁、華碩台灣兩大筆電品牌合作，消費者購買指定款AI PC，除了最高享5,000元折扣，在原廠2年保固之外再送延長保固多1年，等於提供3年保固。

各大筆電廠期望AI PC能夠帶動新一波換機潮，目前對於AI PC的定義其實相當廣泛，只要不依賴雲端，電腦能夠執行生成式AI，就能稱為AI PC。微軟另外推動「Copilot+ PC」，首批上市產品搭載高通Snapdragon X平台處理器。

全國電子看好AI PC熱潮，最新登場的開學季活動，以AI PC為主軸，推出眾多優惠，以下整理8大促銷。

● 購買宏碁、華碩指定AI PC，最高省5000元，再送延長1年保固。

● 購買任一筆電／桌機，上網登錄可抽三星32吋Odyssey OLED 4K電競螢幕(市價36,900元)、三星Z Flip6手機等好禮，獎品總價值超過10萬元。

● 買Microsoft 365(市價2,190元)贈送同額2,190元筆電購物金(購物金限購買RTX3050顯卡以上筆電適用，Apple品牌除外)。

● 任一筆電加價1,990元，可購買中古筆電收購msi電競螢幕(市價3,990元)，還可享最低63折加購飛利浦指定電鬍刀。

● 購買任一筆電除贈送羅技滑鼠墊，單品滿20,000元再加碼送肩背手提包或USB HUB。

● 購買四大家電並完成安裝贈送10,000元筆電購物金。

● 參加全國電子官方LINE遊戲「轉動開學季」，天天抽天天折3C購物金，幸運民眾有機會抽到20,000元獎學金（限兌換指定商品）。指定iPad還享教育優惠價95折。

中古筆電收購中古筆電收購

中古筆電收購

線上估價

Review of the AMD Radeon RX 7900 XTX and XT: the XTX beats the Nvidia RTX 4080 for $200 less, except in power efficiency and ray tracing, and the XT comes close 中古筆電收購

發佈留言取消回覆

發佈留言 取消回覆

發佈留言取消回覆