Overclocked i7-4930K versus stock i7-5960X for chess

[gordonr]

Any opinions on how a stock i7-5960X system would compare to a i7-4930K (overclocked to 4.1 GHz)?

I have an overclocked 4930K and it’s not reliable enough. Overnight analysis sometimes results in a box that has fell over. I’ve tried fixing without success. Hence I now want a stock CPU emphasising reliability over performance. I’m looking at a i7-5960X and have compared general benchmarks for both CPUs but wanted to know if anyone can comment specifically for chess.

The i7-5960K has 8 cores and stock clock is 3 GHz. My i7-4930K has 6 cores but overclocked at 4.1 Ghz. Is Stockfish/Komodo going to be significantly faster on the stock 5960K? I’m assuming hyper threading enabled so 16 threads versus 12 threads respectively.

Thanks for any advice.

[Sean Evans]

Any opinions on how a stock i7-5960X system would compare to a i7-4930K (overclocked to 4.1 GHz)?

I have an overclocked 4930K and it’s not reliable enough. Overnight analysis sometimes results in a box that has fell over. I’ve tried fixing without success. Hence I now want a stock CPU emphasising reliability over performance. I’m looking at a i7-5960X and have compared general benchmarks for both CPUs but wanted to know if anyone can comment specifically for chess.

The i7-5960K has 8 cores and stock clock is 3 GHz. My i7-4930K has 6 cores but overclocked at 4.1 Ghz. Is Stockfish/Komodo going to be significantly faster on the stock 5960K? I’m assuming hyper threading enabled so 16 threads versus 12 threads respectively.

Thanks for any advice.

Hyper-threading should be shutoff when using chess engines to reach maximum power.

[gordonr]

Hyper-threading should be shutoff when using chess engines to reach maximum power.

I followed this advice for many years. Then I saw some posts here saying that it may no longer hold for recent versions of Stockfish or Komodo. I then did my own benchmarking and saw that hyperthreading enabled was better for my setup. I don't claim it's best for all hardware and engine combinations.

[Laskos]

Hyper-threading should be shutoff when using chess engines to reach maximum power.

I followed this advice for many years. Then I saw some posts here saying that it may no longer hold for recent versions of Stockfish or Komodo. I then did my own benchmarking and saw that hyperthreading enabled was better for my setup. I don't claim it's best for all hardware and engine combinations.

It's valid for 4 i7 cores, going from 4 to 8 threads. I doubt that 8 to 16 will be going to bring benefit, as parallel implementation is not very efficient at higher number of cores. If you get above 20% NPS speedup 8->16, it might be ok, although 25-30% would be even better.

As to the original question, you will get no better results, probably worse, upgrading from the overclocked 4930K to stock 5960X. The comparison is direct, not only the total frequency is higher, but it's on fewer cores (6x4.1 > 8x3.0), and fewer cores is better at total fairly equal frequency. I think you can overclock easily and stably the 5960X to its Turbo Boost frequency IIRC of 3.5 GHz, using a crappy cooler. In this case you will have a tiny (maybe 5%-10%) improvement in effective speed (don't look at NPS, its meaning is strength-wise) for the 5960X over the overclocked and unstable 4930K.

[Zenmastur]

Any opinions on how a stock i7-5960X system would compare to a i7-4930K (overclocked to 4.1 GHz)?

I have an overclocked 4930K and it’s not reliable enough. Overnight analysis sometimes results in a box that has fell over. I’ve tried fixing without success. Hence I now want a stock CPU emphasising reliability over performance. I’m looking at a i7-5960X and have compared general benchmarks for both CPUs but wanted to know if anyone can comment specifically for chess.

The i7-5960K has 8 cores and stock clock is 3 GHz. My i7-4930K has 6 cores but overclocked at 4.1 Ghz. Is Stockfish/Komodo going to be significantly faster on the stock 5960K? I’m assuming hyper threading enabled so 16 threads versus 12 threads respectively.

Thanks for any advice.

What exactly is the system doing that it shouldn't be?

What temp is each core reaching during over-clocking?

Are all core overclocked the same or do you OC them individually.

What speed is your memory/ how much memory/ have fast are you running it?

I suspect that you can make your system stable with a little tweaking. But there is no way to know without more info on your setup. 4.1 Ghz isn't that much of an over-clock. Even so, some CPU's won't tolerate it even if kept cool. Same goes for MB's and memory. So, there is the possibility your just trying to get too much from your particular set up. The question is, which component/setting is causing the problem, CPU, MB, Memory, Video card, other installed device or a bios setting?

Regards,

Zen

[gordonr]

Thanks Kai and Forrest. Much appreciated.

I bought the 4930K system overclocked, leaving it to the experts (which I am not). If overclocking is involved or problematic, I'll just avoid it and accept some performance loss. I don't care enough about max performance - just decent performance and being reliable.

It now occurs to me that the system used to sometimes run at 4.1 GHz but then be automatically "stepped down". I assume some thermal checker protecting the CPU. I didn't use a utility like Speccy back then so maybe I've been overestimating how often it would be running overclocked?! Anyway, I can't reproduce this "stepping" behaviour today via the BIOS. Now it will run at max load till it falls over.


>> What exactly is the system doing that it shouldn't be?

I spent time cleaning any dust out the case/fans/etc; trying various BIOS settings including preset defaults (BCLK Freq, CPU Strap, AI Overclock Tuner, CPU Core Ratio, etc.). I never disabled any thermal checking in the BIOS. Then my PC sometimes wouldn't boot; Windows would hang; or blue screen after some short engine analysis.


>> What temp is each core reaching during over-clocking?

When running at 4.1 GHz, Speccy shows average core temp climbing to around 90 C. This sounds far too high and not surprisingly would make it unstable. But I couldn't figure out how to lower the overclocking manually or automatically and achieve a stable system - it still failed in some manner.


>> Are all core overclocked the same or do you OC them individually.

The same. (BIOS: "CPU Core Ratios" = Sync all cores)


>> What speed is your memory/ how much memory/ have fast are you running it?

32GB KINGSTON HYPERX BEAST QUAD-DDR3 2400MHz X.M.P
Speccy says: DRAM Frequency 1166.4 MHz


>> I suspect that you can make your system stable with a little tweaking.

Here's where I settled at...
- ran an "OC Tuner" within the BIOS with hyperthreading enabled
- tried running an engine using 8 out of 12 threads; temp climbed to around 90 C and it fell over
- tried with 6 out of 12 threads; temp sits between 70 and 80 C and not yet fell over

Speccy says (which I don't claim to fully understand):

Core Speed # Multiplier # Bus Speed # Rated Bus Speed
Core 0 4123.7 MHz # x 33.0 # 125.0 MHz # 3998.8 MHz
(same for all 6 cores)


So I'm using the system at no more than 50% in terms of Windows Task Manager. But this is at a constant overclocked 4.1 GHz. It seems stable and with ok performance.

Thanks again.

[Matthias Gemuh]

90 C means your CPU fan needs new contact paste (thermal paste).

[Zenmastur]

Thanks Kai and Forrest. Much appreciated.

I bought the 4930K system overclocked, leaving it to the experts (which I am not). If overclocking is involved or problematic, I'll just avoid it and accept some performance loss. I don't care enough about max performance - just decent performance and being reliable.

It now occurs to me that the system used to sometimes run at 4.1 GHz but then be automatically "stepped down". I assume some thermal checker protecting the CPU. I didn't use a utility like Speccy back then so maybe I've been overestimating how often it would be running overclocked?! Anyway, I can't reproduce this "stepping" behaviour today via the BIOS. Now it will run at max load till it falls over.


>> What exactly is the system doing that it shouldn't be?

I spent time cleaning any dust out the case/fans/etc; trying various BIOS settings including preset defaults (BCLK Freq, CPU Strap, AI Overclock Tuner, CPU Core Ratio, etc.). I never disabled any thermal checking in the BIOS. Then my PC sometimes wouldn't boot; Windows would hang; or blue screen after some short engine analysis.


>> What temp is each core reaching during over-clocking?

When running at 4.1 GHz, Speccy shows average core temp climbing to around 90 C. This sounds far too high and not surprisingly would make it unstable. But I couldn't figure out how to lower the overclocking manually or automatically and achieve a stable system - it still failed in some manner.

The first thing you have to do is get your core temps down to something reasonable. Anything past 70C is too hot! Your in the danger zone.

1.) Check the heat-sink contact area for thermal paste. Some of the cheap stuff will run when hot and you can lose good contact. USE a high quality silver paste if possible.
2.) Check the CPU voltage. It could be set too high. I^2*R can make it impossible to keep the CPU cool. It should be higher than spec for over-clocking, but setting it too high for a few extra MHz is a good way to cause problems for yourself. This is a common mistake – excess voltage kills CPU's all the time. Use only as much voltage as required to make the CPU stable at higher clock-rates.
3.) The base clock seems way too high and the multiplier way too low. I run my system at 4.7 Ghz. The base-clock is set at 107 and the multiplier at 44. 44 * 107 = 4.708 Ghz. It runs stable and core temps stay around 65-70C on a $30 air cooler. Having too high of a base-clock stresses everything else in the system other than the CPU. Most MB components won't take this kind of abuse. Only very very little advantage is gained by running the base clock this high and it causes problems like system instability.
4.) Try 100 * 41. If that works then you can try bumping the base-clock and droping the multiplier. Ie 102.5 * 40 then 105 * 39 etc. You can continue doing this until it becomes unstable.
5.) If it doesn't work at 100 * 41 then drop the over-all speed until it's stable. i e 100 * 40 then 100 * 39. Then go back to item 4 and adjust your base clock up and the multiplier down keeping CPU Speed constant at whatever speed you determined that it will run stable at.
6.) For chess software there is no need to run memory beyond its specs. There is no upside to doing this. Chess programs don't use a lot of memory band width. If anything I would set the memory to a configuration that minimizes latency even if that means running the memory well below its maximum frequency.
E.G. the CAS latency of your memory is 9.167ns at its spec'd freq. Running it at 1600 at a CL7 (if it'll run at those settings) is a latency of 8.75 ns. Other settings to try would be 1866 @ CL8 and 2133 @ CL9. There is only a small % chance it will run at one of these settings but its worth a try. Since your not to experienced with OC'ing stay away from odd memory speed like 1710 etc and don't mess with any of the mem-timings other than Cas as you can make it hard on yourself!
7.) Get a program like Real_temp that will monitor each thermal-couple and sound a user settable alarm if any core goes over the specified temp.

I'm sure with a liitle patience you're system can be made to perform well and be ROCK-SOLID!

Regards,

Zen

[gordonr]

Thanks everyone for the great advice.

Firstly, I'm not going to rush into buying an unclocked 5960X system. That now sounds like quite a bit of money with not enough benefit. I'll put some new high quality thermal paste on my 4930K. Then I'll get Real_temp and look at the BIOS settings suggested by Forrest.

cheers

Gordon