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Comment by Racing0461 | Hacker News Reader

Single core performance?

All i'm seeing is the confirmation that independently parallalizable tasks finish twice as fast on a cpu with twice the cores. cool, amdahl's law is proven.

The handbrake one, all the times seems similar indicating similar single core perf.

This matters for me since single core perf is pretty important for visual studio/other software with alot going on feeling "snappy" even tho the actual compiling/rendering might be faster and scale with moree cores.

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Threadripper is as the name implies, purely MT focused.

I run simulations that are inherently completely single-threaded and I lean on Geekbench which tend to be a good predictor for me. As far as I can tell, Intel still holds the crown in absolute ST perf, granted at horrific efficiencies: https://browser.geekbench.com/processor-benchmarks/ (be sure to ignore the "Top Single-Core Results" which AFAICT is full of BS numbers). Intel's latest 14900K isn't there yet, but should be a smidgen faster: https://www.techspot.com/news/100034-intel-core-i9-14900k-to...

> All i'm seeing is the confirmation that independently parallalizable tasks finish twice as fast on a cpu with twice the cores. cool, amdahl's law is proven.

Yes, but if you can squeeze more cores in the same space (and/or power) envelope, and not suffer a performance per core penalty, you're winning.

Single core should be not much worse than Ryzen.

Yep seems about the same single thread wise which is a bit weird since 7950x3d base clock is 4.2 whereas the 7995wx is 2.5.

https://www.cpubenchmark.net/compare/5726vs5234vs3862/AMD-Ry...

Single threaded tasks should never run at the base clock. The base clock can pretty much be thought of as the minimum clock speed you should see when all cores are maxed out and the thermal solution is only just meeting the spec.

I still want my computer to remain responsive even when I'm rendering in the background.

I doubt 2.5ghz vs 4.2ghz is going to make any real difference to "responsiveness". The more pressing concern would be making sure the kernel actually schedules foreground workloads promptly.

Typical desktop OS's don't have proper prioritization and terrible schedulers. It's definitely not the hardware.

Maybe i'm missing why it doesn't matter. Ryzen runs at 4.5 base clock, TR Pro runs at 2.5 base clock, upon booting up nothing is happening so each cpu runs at their base clock. I open something like visual studio that isn't too intensive so each cpu doesn't realize it needs to boost. Won't the ryzen with 4.5 base clock feel snappier than the 2.5 one when vs loads?

When a pretty big task (compiling, rendering) activates the scheduler and causes the cpu to boost to their respective 5 ghz or w/e, then yeah the numbers would be the same, but they don't be at the beginning when i'm dragging windows around and right clicking on stuff in visual studio. I don't believe this feeling is reflected in the scores.

No. None of what you're writing is accurate. No processor made in the last decade will ever idle at the base clock. Any modern processor idles far, far lower than that, approximately 1Ghz, maybe even lower. Idling at multiple gigahertz would be a huge waste of energy. The minimum clock speed is not correlated to the "base clock" at all.

It takes tens of milliseconds to reach the boost clock: https://stackoverflow.com/a/64254459

The base clock is entirely irrelevant to everything you are talking about. Please reference my earlier comment for the meaning of "base clock": https://news.ycombinator.com/item?id=37980293

Interesting, i'l l have to do more research here since the reason i went with my current setup is based on this thinking.

While technically correct for longer time frames, setting a performance governor on both windows and linux basically means that it comes out of idle at the max allowable frequency. In order to achieve this it basically means that idle isn't adjusting the clock rates (to avoid the transition latencies) for idle times less than 2x those latencies. Depending on the core/firmware/etc it may be gating the clock, or clock skipping, which can save some power

And yes it can waste energy you can measure with the your battery monitor (or UPS/PDU) but its also possible to measure the interrupt handling latency/etc, and for some cores it can make a very noticeable difference to desktop latency if you happen to be sensitive to such things.

While I've posted elsewhere about clamping the clock rate to save power, I also do the converse when plugged in by cutting off the bottom 2/3rds of the frequency range. This results in a far more responsive desktop in linux and even windows to a lesser extent.

>> and the thermal solution is only just meeting the spec.

Ok, so, as I alluded to earlier... make sure to have better-than-minimum-spec cooling to let the processor indefinitely run all cores at the boost clock (or very close to it).

It's been a long time since I've seen a desktop/workstation processor limit itself to the base clock for any reason.

Also, I agree with dralley. Clock speeds are unlikely to be the issue there anyways.

That's more of a software thing than hardware. You could do that in the 80's with the right software, but most modern operating systems suck at realtime stuff (and ui is realtime).

+1. it's great that it compiles code faster, but i would also like when i'm writing code and hit enter, a newline is added and all lines under it goes down by 1 without any "lag".

That's why i decided to go with a 5950x + 3090 rtx + gamer ram for my current "workstation" instead of a 5995wx + rtx 6000 + ecc ram for my current machine. even tho its not workstation rated, it seemed like the better way to go for quality of life feel.

When the next generation of cpu/gpu/ram drops in the next couple eyars, i can re-evaluate the gamer vs professional offering to see if it matters.

Having run a 3945WX machine side by side with same era intel and AMD desktops the Threadripper Pro was the more “responsive” machine, but it was minor enough you would have had to have them side by side to really notice.

Once there were a lot of programs in flight it started making a larger and larger difference. Now half my family and friends have TR Pro systems bought refurbished (they watched eBay) because they loved mine so much.

The TR Pro cpus with the same cores as ryzen equilivalent should have similar performance as they have similar specs.

https://www.amd.com/en/products/cpu/amd-ryzen-threadripper-p... vs https://www.amd.com/en/products/cpu/amd-ryzen-9-7900x

Its usually the ones with more cores than the max ryzen cpus that have to make tradeoffs and seeing how it affects day to day use. (the 32, 64, and in this case the 96 core ones).

since a few generations ago boosts have become so good that for many use-cases base clock don't matter that much

AFIK it's basically tweaked AMD EPYC™ 9654 with much higher boost and some other changes, so that's probably where the base clock comes from

some situations where the base clock might still matter:

- you perfectly max out CPU utilization (no I/O, hardly cache misses, etc.) and at the same time have exactly only the thermal headroom from the spec and run it for a "long" time

- you want to max optimize for watter/perf the best power efficiency is likely around the base clock (for this one because of my assumption of it being more or less a tweaked server processor, on a typical consumer desktop PC I would say likely quite a bit below the base clock)

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