Tuesday, January 18th 2022
PSA: GPU-Z shows PCI-Express x16 for Radeon RX 6500 XT / Navi 24. It really is x4
AMD announced the Radeon RX 6500 XT and RX 6400 at CES just a few days ago. These new entry-level cards debut the company's first 6 nm GPU, codenamed "Navi 24"—the smallest chip from the RDNA2 family. Navi 24 is barely the size of a motherboard chipset, roughly 100 mm² in die size. The chip only features a 64-bit wide GDDR6 memory interface, needing just two memory chips to achieve 4 GB of memory size. While AMD has been fairly quiet about it, people quickly found out that the Navi 24 GPU only uses a PCI-Express 4.0 x4 host interface. While the physical connector is x16, there is only enough signal traces for x4.
Even the most updated 2.43.0 public version of GPU-Z misreports the bus interface as PCIe x16 4.0 though, which will certainly lead to confusion in the reviewer community who trust GPU-Z to report the correct specs and speeds for their articles. Maybe that's the reason why AMD has decided to not send us a sample this time—a first in 15 years.
Update Jan 20th: GPU-Z 2.44.0 has been released, which properly reports the PCIe bus configuration of RX 6500 XT.
The underlying technical reason for this misreporting is that since a few generations AMD has designed their GPUs with a PCI-Express bridge inside, which makes things much more flexible and helps to separate the IP blocks. The bridge distributes the transferred data to the various subdevices, like the graphics core and HD Audio interface, as displayed in the screenshot above. Internally the GPU core operates at x16, despite the external PCIe 4.0 interface, only the link between the GPU's integrated bridge and the motherboard runs at x4. Since current GPU-Z does not know that the running GPU is Navi 24 it asks the graphics core for its link speed and width, which happily reports "PCIe x16 4.0" (instead of "PCIe x4 4.0"), which is of course correct from the perspective of the graphics core. The problem is that upstream a bottleneck exists that operates at only x4. For supported GPUs, GPU-Z is of course aware of such a topology and will check the upstream devices for bottlenecks, but this capability has to be added on a case-by-case basis. This situation also affects the reported PCIe speed, too. For example on older Intel systems, which don't support PCIe 4.0. Internally the GPU always operates at PCIe 4.0, even on PCIe 3.0 or older motherboards.
We plan to correct this with an update to GPU-Z shortly.
Update Jan 20th: GPU-Z 2.44.0 has been released, which properly reports the PCIe bus configuration of RX 6500 XT.
We plan to correct this with an update to GPU-Z shortly.
57 Comments on PSA: GPU-Z shows PCI-Express x16 for Radeon RX 6500 XT / Navi 24. It really is x4
In both case, it was know before hands that the reports would be negative but still. Just don't make crappy product then ! lol
But i am a bit more concerned about AMD doing this in a price range that most people are able to afford and they expect to ship a shit tons of cards. On the Nvidia Side, they are so overpriced that there are limited amount of people that are able to afford it and it's probably just a paper launch anyway.
Performance is bad, vram capacity is bad, pcie link speed is comically gimped via bridge, Pricing is bad...
I mean I'm sure probably people will buy it, but I am amazed AMD would even put their names on this. The tarnishment to their reputation is cannot be worth the benefit.
This product is so bad it almost warrants a new brand altogether. Like a "Geo Metro 3D Accelerator Board" or "Pandemic Graphics"
Look at how bad AMD cards do with 16 GB ram on Battlefield 2042
www.tomshardware.com/news/battlefield-2042-pc-performance-benchmarks-settings
compared to when they have 32 GB available:
www.techspot.com/article/2364-battlefield-2042-benchmarks/
When lower vram AMD cards run out of system ram or bandwidth to that resource, they take a dump in many cases.
web.archive.org/web/20190110110649/http://weeklybiz.chosun.com/site/data/html_dir/2018/08/31/2018083101687.html
Article is in Korean, btw.Fair point, though considering the market these cards are targeting (that is, if they even manage to exist outside of paper launches), I don't think it will be that bad.
Though, picking out a dying game seems a bit odd.
It's ugly!
That puny 16MB of infinity cache is going to be doing some heavy lifting for sure.
So why would Steve post the PCI tests results for the RX5500 XT if it did not not reflect the RX 6500 XT results as well?
Perhaps the 6500XT doesn't suffer the same fate as the 5500XT because of RDNA2's infinity cache. At 16MB it's hard to see how much good it can do, but I'm not going to place bets for or against it.
Either way, less than 24 hours left to wait.
And probably she lies - the usual business practice.. :kookoo: :rolleyes:
:peace:
HUBs video revealed some important information that as it was assumed that the lower end AMD cards would not be as affected by PCIe scaling as the higher end cards.
I am thinking that is why the 5500xt was limited to x8 in the first place. It allowed for more market segmentation as the 4GB card would have only fell short in 2 or 3 games behind the 8GB card had it been running pcie4 x16 or even pcie3 x16.
Heck, I could even consider it false advertisement.
Oh, and if he's effectively passing off 6500 XT numbers as 5500 XT's, and if there's an effective NDA over the RX 6500 XT, that's also breach of NDA.