Earlier quoted context omitted.
The "games don't use CPU" line is only really true for multiplatform games that must also run on the low performance PS4/XBox One AMD Jaguar CPUs. If we look at PC exclusives [1] then we can see that these are extremely CPU-hungry games. This hunger only goes up if we want to achieve a framerate higher than 60, say going for 144. I personally have an i7 @ 3.8 GHz with GTX 1060 and none of these games can hold a stabl…
Does it matter that every piece of scientific evidence shows that humans can't see anything at more than ~70hz?
AMD Ryzen 7 1800X Benchmarked – Giving Intel’s $1000 Chips A Run For It
201–210 of 278 posts
Re: AMD Ryzen 7 1800X Benchmarked – Giving Intel’s $1000 Chips A Run For It
#202That does not really make sense. Why would physics simulation and prime calculation be so much slower? I would not trust those benchmarks.
My guess would be branching behavior. The Intel branch predictor could be better for that sort of stuff.
Re: AMD Ryzen 7 1800X Benchmarked – Giving Intel’s $1000 Chips A Run For It
#203Earlier quoted context omitted.
The i7-7700K has only 4 cores. The comparison with the 6900K is more fair.
6900K has 40 PCIE lanes and that's raison d'etre of this chip. So it is not really fair to compare the more expensive chip and then ignore exactly that thing, that makes it expensive.
Re: AMD Ryzen 7 1800X Benchmarked – Giving Intel’s $1000 Chips A Run For It
#204Earlier quoted context omitted.
My guess would be branching behavior. The Intel branch predictor could be better for that sort of stuff.
That might be true of the physics simulation but I think that's more likely Intel's better vector processing resources. With a prime search the branches involved ought to be a combination of the trivially easy ones that any predictor should be able to handle and the super high entropy ones that no predictor can guess. So if anything doing badly on the prime test is an indication that it was AMD's good branch predicto…
Re: AMD Ryzen 7 1800X Benchmarked – Giving Intel’s $1000 Chips A Run For It
#205I predict in the future that AMD will come to dominate the home/enthusiasts CPU market, and intel's low-power CPUs will dominate enterprise along with whoever comes out with a CUDA competitor.
1. https://www.google.com/amp/s/www.fool.com/amp/investing/2017...
Re: AMD Ryzen 7 1800X Benchmarked – Giving Intel’s $1000 Chips A Run For It
#206Earlier quoted context omitted.
TDP is a bit tricky to compare in this situation. The TDP of Intels HEDT chips is dictated by their 256-bit wide AVX units which drive power consumption through the roof when fully loaded, and the chips don't get nearly as hot when AVX isn't being used. Ryzen doesn't have this edge case because it sticks with 128-bit SIMD units and runs AVX instructions over two clock cycles. I expect the "140W" Intel part will have…
Intel chips use a lower base clock frequency when they're running AVX code than when they're running non-AVX code for the very reasons you mention. In Intel's example[1] they talk about a base freqeuncy of 2.3 GHz without using AVX dropping to 1.9 with AVX[1]. That drop isn't much in frequency terms but you also have to figure in the voltage drop that the lower frequency allows you to cut power much more than you cut…
I.e., LAPACK/BLAS benchmarks are just really big linear algebra matrix problems, so obviously your pre-fetch and branch prediction performance will be significantly better since you aren't dealing with interrupts, locatedb, or Windows DCOM events firing off in the background. You have a huge set of matrices with a very predictable set of branches, fetches, and decodes, so obviously your CPU can optimize for that load, you're just paying for it in latency on the back-end (RAM fetches are the new disk swap ;)).
On all those benchmarks, (i.e. your standard LU matrix decomposition which previously was the basis of the LAPACK benchmarks, though things might have changed in the ~10 years since I've really looked at things) isn't CPU-bound anymore, so of course your instruction-per-cycle load on the CPU isn't where you'll be bottlenecking (and hasn't been since "let's avoid floating-point operations and just use static look-ups instead since we don't want the 10x cost of using the FDIVP instruction!"). Your processor can very easily anticipate from where in that sparse-matrix your next data fetch is going to be. It's the cost of that RAM fetch[1] going along that copper trace which is going to be where you're going to bottleneck on any heavy numerical computation.
The power consumption on your CPU might drop a nominal amount which is great for those marketing white papers, but for a numerically heavy load, you're paying just as much (in total power consumption per 4U in the data center, total heat generation/dissipation within the case, and total processing time) on the back-end for those fetches.
[1] https://i.stack.imgur.com/a7jWu.png (I normally cite academic references, but this is 'good enough' to convey my point, I hope).
Re: AMD Ryzen 7 1800X Benchmarked – Giving Intel’s $1000 Chips A Run For It
#207Wow... I really hope this is true and that it's a sign that AMD have their mojo back. Partly because I have a sentimental favoritism towards AMD, and partly because Intel (and Nvidia) need competition.
An AMD 40Mhz 80486 was my first build so I also have a soft spot. At the time it was the fatest x86 one could buy. Gees I even remember lusting after the Ati 8514 Ultra, one of the earliest GPU accelerators, clone of IBM's high end workstation standard of the early 90s, as a teenager. Wow I'm getting old. Conversely, though I admire Intel for its central place in advancing computing itself, I cannot love the company…
I also like AMD because they've been at least a little bit more "open source friendly" than some of their competitors (cough Nvidia cough). Which is not to say that they couldn't do more, of course.
Re: AMD Ryzen 7 1800X Benchmarked – Giving Intel’s $1000 Chips A Run For It
#208Earlier quoted context omitted.
The "games don't use CPU" line is only really true for multiplatform games that must also run on the low performance PS4/XBox One AMD Jaguar CPUs. If we look at PC exclusives [1] then we can see that these are extremely CPU-hungry games. This hunger only goes up if we want to achieve a framerate higher than 60, say going for 144. I personally have an i7 @ 3.8 GHz with GTX 1060 and none of these games can hold a stabl…
Just curious: why do you want to run a turn based game like civ6 at 144fps? Or for that matter anything except super reaction-dependent FPSs?
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[1] This being all reaction-dependant games, doesn't have to be FPS. Even fast paced pong qualifies.
Re: AMD Ryzen 7 1800X Benchmarked – Giving Intel’s $1000 Chips A Run For It
#209Earlier quoted context omitted.
6900K has 40 PCIE lanes and that's raison d'etre of this chip. So it is not really fair to compare the more expensive chip and then ignore exactly that thing, that makes it expensive.
Many more people care about core count than PCI-E lanes… Core count is the probably the most important thing about a CPU.
Re: AMD Ryzen 7 1800X Benchmarked – Giving Intel’s $1000 Chips A Run For It
#210Earlier quoted context omitted.
ECC (error-correcting codes) don't completely eliminate errors — they reduce probability of them happening — so even with ECC memory you're still accepting that it's perfectly OK that 0 is sometimes 1, just a lot less likely. No absolutes here, unfortunately.
This EXTREMELY reduces the probability that a bit flips happens. And consumer PCs (or mobile devices) are the only devices where there is no ECC memory, RAM is the only place in such devices where there is no error detection and/or correction.