Why do people always make the same assumption that you get a 100% linear perf scaling with increased clock ? This never happens, atleast in majority of apps. 8700 at 4.3 Ghz with HT will definitely be faster than 8600k at 5.0 Ghz for MT workloads. Proof : have a look at 8600k at 4.8 Ghz not even close to 8700k (8700 has the same all core turbo)
https://www.techpowerup.com/reviews/Intel/Core_i5_8600K/9.html
TPU scores are without MCE . HWC scores with MCEAre you sure MCE isn't enabled. That is a problem with 8700K reviews.
I am getting to the point that I am getting ready to buy what ever CPU comes into stock first I am sick of waiting.
Because within the relatively tight frequency range within which most comparisons are run, performance does scale relatively linearly in many apps. From 2 to 3 to 4GHz might not be linear at all, but from 3.6 to 3.8 to 4.0GHz will appear much more so.Why do people always make the same assumption that you get a 100% linear perf scaling with increased clock ? This never happens, atleast in majority of apps. 8700 at 4.3 Ghz with HT will definitely be faster than 8600k at 5.0 Ghz for MT workloads. Proof : have a look at 8600k at 4.8 Ghz not even close to 8700k (8700 has the same all core turbo)
https://www.techpowerup.com/reviews/Intel/Core_i5_8600K/9.html
Imo add a cheap non z mb to the 8400 and 8700. Run your 3000c15 ram at 2666c14 and they are the sweet gaming deal.Honestly, I think the 8600K is in an awkward spot price wise and apart from gamers I really can't see its value when compared to other products around its price range.
As I said earlier, it's basically the same price as the 8700 non k once you factor in the price of a HSF, but even when overclocked to 5GHz it is only 400MHz faster than the 1C turbo of the 8700. Sure, it will be 700MHz faster when all 6 cores are under load, but if you are actually doing something that is pegging all 6 cores at full load you may as well get the 8700 because it has HT, and in terms of MT throughput a 6C/12T @ 4.3GHz >>> 6C/6T @ 5GHz
There is a difference between linear and perfect 100% clock to perf scaling. There are very few cases where a 10% clock increase gives 10% perf gain . In most cases it’s probably between 6-8% perf gain for 10% clock increase.Because within the relatively tight frequency range within which most comparisons are run, performance does scale relatively linearly in many apps. From 2 to 3 to 4GHz might not be linear at all, but from 3.6 to 3.8 to 4.0GHz will appear much more so.
There is a difference between linear and perfect 100% clock to perf scaling. There are very few cases where a 10% clock increase gives 10% perf gain . In most cases it’s probably between 6-8% perf gain for 10% clock increase.
Your example doesn't prove non-linearity, though. If perf increases 6% for a 10% clock increase, then another 6% for another 10% clock increase, that's linear, just that that slope is less than one.There is a difference between linear and perfect 100% clock to perf scaling. There are very few cases where a 10% clock increase gives 10% perf gain . In most cases it’s probably between 6-8% perf gain for 10% clock increase.
Your example doesn't prove non-linearity, though. If perf increases 6% for a 10% clock increase, then another 6% for another 10% clock increase, that's linear, just that that slope is less than one.
7820X also has 4 more threads than the 8700K.
Undervolt/underclock it will you hit the number you want.Any chance we could get like a low powered i7 8700t 25w or 35w part? I could for sure use a 6c/12t part but would love a energy efficient ultra low power version. I know the i7 8700 non "K:" version is 65w already so maybe if they drop the stock clock to something like 2.6Ghz with a turbo boost up to 3.6Ghz would be perfect for me.
Get i7-8700. Set power limit to 35 W in BIOS or Intel Extreme Tuning Utility. No need to wait. Plus, power limit can be set back to 65 W, for flexibility of being able to use high frequencies, whereas the T models will be stuck at its rated frequencies.Any chance we could get like a low powered i7 8700t 25w or 35w part? I could for sure use a 6c/12t part but would love a energy efficient ultra low power version. I know the i7 8700 non "K:" version is 65w already so maybe if they drop the stock clock to something like 2.6Ghz with a turbo boost up to 3.6Ghz would be perfect for me.
Yeah I kinda figured I could underclock, Just thought lower clocked lower power part would be a cheaper buy for me.Undervolt/underclock it will you hit the number you want.
Wow never know that was a thing? first time I ever heard you could change power and TDP limits. I Know you can add and take away voltages but not sure how one would go about changing wattage's from like 95w to 35w.Get i7-8700. Set power limit to 35 W in BIOS or Intel Extreme Tuning Utility. No need to wait. Plus, power limit can be set back to 65 W, for flexibility of being able to use high frequencies, whereas the T models will be stuck at its rated frequencies.
60% is total nonsense to start with.
Clock speed scaling is much closer to 1:1
Here is the picture of 8600K OC to 5.5GHz.
http://abload.de/image.php?img=5500-5090-3866-cb15-1dnsw3.png
Cinebench @5.5GHz = 1385
Here is picture of the 8600K OC to 4.8GHz.
https://tpucdn.com/reviews/Intel/Core_i5_8600K/images/cinebench_multi.png
Cinebench @4.8GHz = 1196
5.5/4.8 = 15% clock-speed increase
1385/1186 = 16% performance increse.
There are NO scaling issues at all moving from 4.8GHz to 5.5GHz.
Performance did not fall off, as he keeps erroneously predicting.
I never argued against linear perf scaling. I said perf never scales 1:1 with clock increase and thats a measurable fact.Your example doesn't prove non-linearity, though. If perf increases 6% for a 10% clock increase, then another 6% for another 10% clock increase, that's linear, just that that slope is less than one.
I could for sure use a 6c/12t part but would love a energy efficient ultra low power version.
Thats a ridiculously biased way to drive an explanation. You cannot arbitrarily take two different systems with different memory speeds and calculate core clock speed scaling. the 8600k at 5.5 Ghz is running at 1933 Mhz (DDR4 3866 Mhz) while the tpu review runs at DDR4 3200. Why don't you use the tpu 8600k results at stock with 4.1 Ghz all core turbo and 4.8 Ghz OC.
4.1 Ghz CB R15 MT score - 1051.66
4.8 Ghz CB R15 MT score -- 1196.14
1196.14/1051.66 = 1.137
4800/4100 = 1.170
So for a 17% clock speed scaling you get a 13.7% perf gain. 13.7 / 17 * 100= 80. Just like what I said. 80% perf gain for 100% clock gain. btw cinebench has very good perf scaling with core clock and maxes out the cpu at 100% usage. Not every app scales as well as CB. Now who was talking nonsense ?
In keeping with the spirit of this being a build thread, what would be the sweet spot for RAM specs for an 8700k, with minimal to no overclocking (though running XMP profile would be acceptable)?
This is probably my sweet spot. 3600, CAS 15 (drop down to 14 if you don't mind dropping frequency), 2 X 8GB, $220. Price becomes prohibitive (for me) for faster + lower latency, which of course would be preferable otherwise.