At its Capsaicin & Cream event today, AMD announced that its High Bandwidth Cache Controller (HBCC), a feature introduced by its "Vega" GPU architecture to improve memory management, will increase game performance tangibly. The company did a side-by-side comparison between two sessions of "Deus Ex: Mankind Divided," in which a HBCC-aware machine purportedly presented 2x better minimum FPS, and 1.5x better average FPS scores, than a non-HBCC-aware system (though the old, trusty frame-rate counter was conspicuously absent from both demos).
AMD also went on to show how HBCC seemingly halves memory requirements, by deliberately capping the amount of addressable memory on the HBCC-aware system to only 2 GB - half of the 4 GB addressable by the non-HBCC-aware system, while claiming that even so, the HBCC-enabled system still showed "the same or better performance" through its better memory management and bandwidth speeds. If these results do hold up to scrutiny, this should benefit implementations of "Vega" with lower amounts of video memory, while simultaneously reducing production costs and overall end-user pricing, since smaller memory pools would be needed for the same effect.
44 Comments on AMD "Vega" High Bandwidth Cache Controller Improves Minimum and Average FPS
this is even more relevant now when gpus do have horsepower to run games at these resolutions.
I have a tuner card in a PCIe X1 slot that sends 24FPS of 1080i plus audio to my GPU directly and then it gets up scaled in hardware, the actual HDMI bandwidth is much higher though. So why can't I run my GPU at PCIE x1?
It's all about where the bandwidth is used and when, and PCIE is over kill for Graphics cards as they are today.
They don't copy, they Innovate & Design. Taking chances, because they have no choice but to do such a thing. Patients paid off with Ryzen, and I can see similar success with Vega.
FYI for all criticizing HBM. GDDR5 or what every you call it is outdated. HBM is the way for the future IMO, and it gets better with each new version coming out.
I mean, they use similar system on professional cards, you know, the one that comes with NAND attached to it? Surely, they know already how things work and they are confident enough they could unlesh this tech to consumer market...
Judging from that picture, HBCC is a memory manager that sits below the L2 that has access to the HBM (presumably HMB2 stacks), system RAM, NAND, and even network (clearly aimed at enterprise customers). It moves pages of memory closer to, and into the L2 that it anticipates being necessary and it removes pages from the L2 that are expired.
Would have to watch the presentation to be sure.
what they are doing doesn't really increase complexity, it just builds on and expands the existing memory organization for more flexibility.
actually from what has been said the controller seems to be meant for caching vram as well but that is done with l2 cache.
My understanding is that what is unique to HBCC is that previous generations of GPUs would only maintain where the data they need is. It would constantly overwrite that data with new data and all I knows about what is contained in that memory is what is in use and what is not. HBCC not only maintains usage, but context. Imagine an asset siting in the system memory like a texture. One frame uses that texture so the GPU pulled it from the RAM and stuck it in the HBC then took a tile of it from the HBC and moved it to L2 where the GPU continued to pull what was necessary from that tile to do actual work on it in the L1 caches. In the next frame, the same texture is used, instead of having to go to the system RAM again to fetch it (because the developer was an idiot and didn't precache it), the HBCC sees that asset already sitting in HBC and starts using it instead of waiting to get it from the system RAM. That saves a few milliseconds in render time.
I think it will help hugely with tessellation, for example.
actually i'm surprised & disappointed that so many devs choose to fill up an entire 4gb, i prefer things to be streamed with maximum detail on nearby objects, aka megatextures (well, even some of the streaming games seem to do a poor job if there is some loss or stutter at 4gb)
a few days ago i had afterburner open in call of duty 4.... only 300something mb used! windows idle was like 100mb