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Nvidia is proposing a beast of a CPU system for Windows PCs

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Re: Nvidia is proposing a beast of a CPU system for Windows PCs

#451

The Qualcomm Snapdragon X2 Elite Extreme trounces Nvidia's chip in single core CPU performance. It beats Intel and AMD's best, too. It has unified memory. It's the only CPU in the same league as Apple's M-series in both CPU performance and power efficiency. And it's available in laptops today, not later this year. People are sleeping on Qualcomm.

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Re: Nvidia is proposing a beast of a CPU system for Windows PCs

#452

The Qualcomm Snapdragon X2 Elite Extreme trounces Nvidia's chip in single core CPU performance. It beats Intel and AMD's best, too. It has unified memory. It's the only CPU in the same league as Apple's M-series in both CPU performance and power efficiency. And it's available in laptops today, not later this year. People are sleeping on Qualcomm.

Is it well supported under Linux?

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Re: Nvidia is proposing a beast of a CPU system for Windows PCs

#453

The Unified Memory pool is what will continue to be the “game changer” in systems architecture, especially outside of data centers. The reality is even cutting edge games and consumer workloads don’t actually take full use of the PCIe bandwidth of the GPU or the bandwidth of its GDDR memory. Even local AI use cases don’t substantially or meaningfully benefit from faster memory, at least to average consumers. A unifie…

> Lets systems optimize utilization based on need, rather than be confined to specific pools The trouble with this is that the different types of memory have different characteristics. Latency for ordinary system memory is actually better than it is for GDDR, because GDDR is optimized for bandwidth. RTX 5090 has 1.8TB/s of memory bandwidth with a 512-bit memory bus. The same bus width for DDR5-9600 would have better…

These are all good points that I agree with but rather than seeing an intractable problem I predict we'll see the role that GDDR would otherwise fill in this scenario replaced by a small block of HBM on the APU die. I don't know if it will ultimately end up unified or not but either way I don't think memory segmentation is the core problem here. Simply not needing to send transfers across the narrow and slow PCIe bus would fix most of the practical problems (at least AFAIK but I'm not an expert).

Transitioning over to wild speculation here, I think that most likely this will be treated as part of an absurdly large L3 (ala 3D V-Cache) or as an additional L4. In either case I expect the latency and power tradeoffs introduced to be tolerated as "good enough" even for the highest end consumer gear. (Actually I wonder if some sort of special case cache would be feasible, with memory addresses flagged by the graphics driver and regular CPU related stuff skipping over it entirely. But by then we've squarely entered the territory of vaguely unhinged rambling on my part.)

Alternatively if the performance caveats are deemed to be important enough to justify the added complexity it wouldn't surprise me to see the HBM treated as an independent memory pool analogous to that of a dGPU. That wouldn't change the current status quo with respect to the GPU APIs but it would significantly ameliorate the memory bandwidth bottleneck for inference workloads and from a software perspective is a drop in replacement. You'd still write the code targeting the dGPU with explicit swapping to RAM but when run on an appropriate APU it would get a massive speedup for free instead of suddenly being starved for bandwidth while also performing unnecessary copy operations.

Re: Nvidia is proposing a beast of a CPU system for Windows PCs

#454
post #257
post #212

Earlier quoted context omitted.

Why do people care so much about single core performance? We are all professionals here and I bet most of our workloads are multi core. I get that these new arm chips from Apple and Qualcomm are great at one thing at a time, but for professional workloads high end x64 chips still cannot be beaten on the desktop.

What x86 chips have the same or higher number of cores in the form factors that these chips are available in and are also more performant? Strix Halo is 16 cores. Intel Core Ultra 9 285HX is 24. Apple is 18. Qualcomm is something similar too but I can’t recall. NVIDIA is 20. Until you get to threadripper/epyc or Xeon territories (completely different form factors and TDPs) the arm chips are ahead on both power and pe…

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Re: Nvidia is proposing a beast of a CPU system for Windows PCs

#455
post #19

Is this essentially an Apple M-Series chip in concept?

No, it stems from a lineage of Tegra chips that pre-date the M-Series. This chip was called GB10. One of its predecessors, GV10 was shipped in 2018. It was a 256 bit, unified-memory system on a chip with a Volta GPU and 12 ARM Cores. GB10 is a 256 bit, unified-memory system on a chip with a Blackwell GPU and 10+10 ARM cores.

Re: Nvidia is proposing a beast of a CPU system for Windows PCs

#456

Earlier quoted context omitted.

> I mean is it possible to make unified memory systems with good performance or is it not really feasible due to memory timing/trace length issues? LPCAMM and similar solutions exist, but have never been demonstrated running at speeds that match what the leading soldered memory systems are using; there's always been some speed penalty. I'm not sure we've ever seen a system demonstrated using LPCAMM or similar for a 5…

> LPCAMM and similar solutions exist, but have never been demonstrated running at speeds that match what the leading soldered memory systems are using; there's always been some speed penalty. LPCAMM2 supports up to 9600MT/s, which appears to be the same speed Apple is using. > I'm not sure we've ever seen a system demonstrated using LPCAMM or similar for a 512-bit bus Servers commonly use a 768-bit DDR5 memory bus pe…

> LPCAMM2 supports up to 9600MT/s, which appears to be the same speed Apple is using.

The difference here is in what the standard defines on paper vs what is actually shipping in products and readily available off the shelf. Who's selling a whole system with LPCAMM2 certified for 9600MT/s? Intel's current-gen Panther Lake top of the line laptop chips are rated for 9600MT/s when using soldered LPDDR5x but only 7467MT/s when using LPCAMM2, according to their current datasheet: https://www.intel.com/content/www/us/en/content-details/8721...

That puts the current Intel-with-LPCAMM2 supported memory speed at 1.5 years and counting lag behind Apple's shipping memory speeds. Intel's own shipping memory speed moved past 7467MT/s a few months earlier than even Apple's.

> Servers commonly use a 768-bit DDR5 memory bus per socket even without LPCAMM and LPCAMM allows shorter traces than traditional DIMMs.

> Moreover, making the bus wider is "easy"

Citations needed. Servers aren't anywhere close to 9600MT/s yet; Intel and AMD are at 6400MT/s. The trace length advantages offered by LPCAMM2 don't necessarily mean the traces for the sixth or eighth channel would be short enough for 9600MT/s (which again, is not yet available even in a 128-bit configuration in shipping hardware). Adding more channels to even a LPCAMM2 configuration means adding more trace length, because only two modules can actually be adjacent to the CPU socket. (Maybe you could get to 512-bit with modules on the front and back of the board while maintaining trace lengths short enough to reach meaningfully higher speeds than regular DDR5, but so far nobody is doing that or even talking about it.)

Re: Nvidia is proposing a beast of a CPU system for Windows PCs

#457
post #307

The Unified Memory pool is what will continue to be the “game changer” in systems architecture, especially outside of data centers. The reality is even cutting edge games and consumer workloads don’t actually take full use of the PCIe bandwidth of the GPU or the bandwidth of its GDDR memory. Even local AI use cases don’t substantially or meaningfully benefit from faster memory, at least to average consumers. A unifie…

And conveniently, by making your machine non upgradeable, it allows the manufacturer to enforce market segmentation / charge a huge premium for small RAM upgrade ( a la Apple)

I wish manufacturers could consider a hybrid approach. There should be no reason an architecture can't support both unified memory (effectively L4(?) cache), and cheaper, upgradeable system memory on sticks for old-school application use.

Re: Nvidia is proposing a beast of a CPU system for Windows PCs

#458
post #434

Earlier quoted context omitted.

>[..] take full use of the PCIe bandwidth of the GPU or the bandwidth of its GDDR memory. I'm honestly a little confused by what you mean here. Why would we want to maximize those things? Games are about consistent output under the frame deadline, not full saturation of the hardware. Why would anyone try to saturate a 5090 with their game? The addressable market is tiny and you'd have to hope their full spec runs as…

You could do some sort of adaptive quality where you spend time incrementally improving fidelity until your frame budget is up. In practice I think that might be trickier than it sounds, but I feel like theoretically there's something there that could get you the best graphics your rig can handle without dropping frames. I've been considering doing something like this when I've been building a game/engine lately.

There's only so high you can go because the game assets have a maximum quality. Maybe you'll be able to max out the 5090 but what about the next flagship GPU?

You're also likely not going to maximize all of bandwidth, compute, etc. because one of them will likely be your bottleneck. And it might be different depending on the GPU, too.

Re: Nvidia is proposing a beast of a CPU system for Windows PCs

#459
post #38

Here is the press release for the actual machine: https://nvidianews.nvidia.com/news/nvidia-microsoft-windows-... I have been somewhat surprised at the lack of commentators observing that this is Microsoft and above all NVIDIA launching a device that is fundamentally at odds with the metered cloud model of AI. When you look at the other announcements and murmurings (better offline BYOK for Copilot, talk of an unmeter…

Maybe. Or they are simply hedging their bets.

They get to keep more Ai usage from big providers, send telemetry, and inject ads.

Re: Nvidia is proposing a beast of a CPU system for Windows PCs

#460
post #307

Earlier quoted context omitted.

And conveniently, by making your machine non upgradeable, it allows the manufacturer to enforce market segmentation / charge a huge premium for small RAM upgrade ( a la Apple)

It doesn't -have- to be that way necessarily... LPCAMM2/SOCAMM2 exist, heck I think Framework is using LPCAMM2 in one of their new laptops. Heck, I'm willing to bet that a lot of manufacturers would rather go that route than soldered in, if for no other reason than the relative cost of warranty work between the two. However, people probably need to stop being obsessed with ultrathin laptops for that to happen.

> However, people probably need to stop being obsessed with ultrathin laptops for that to happen.

I've never been able to understand this. Once we made it down to ~20 mm (which for the record still accommodates dual-stacked SO-DIMMs, a 2.5 inch bay, and a user replaceable battery but not an RJ45 jack) I don't understand what the practical impact of any further reduction is supposed to be. Regardless of how thin you make it the thing will still be a massive rectangle that you can't flex or press on.

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