i5 6500T (Skylake) overclocking on Maximus VIII Ranger (Z170)

[itsakjt]

Hello all and good day! I recently got an i5 6500T for dirt cheap (my old 7600K has a faulty memory controller) and with the modded BIOS (ver. 0018), I was able to overclock it to 4.4 GHz on the Maximus VIII Ranger (Z170). Thing is, as mentioned in many forums, cache performance, especially L1 and L2 is very poor as a result of poor AVX instructions and is worse than stock as well. I just wanted to know that is their any potential fix for it?
Do share your experiences.

 

[DR4G00N]

There's no fix for it that I'm aware of, AVX stops working above 102.9375MHz BCLK on locked Skylake IIRC.

Back before the 7350K existed lots of people on HWBot were pushing i3 6320's for XTU 2-core global points (myself included), but no one could figure out how to keep the AVX performance from going to crap beyond the aforementioned BCLK thus giving a very low score.

 

[itsakjt]

Thanks for the response. I am still looking out for an used 7600K or a 7700K but these are really hard to find here for a decent price.
Coming to the real question now, what do you guys suggest? Shall I continue with my i5 7600K @ 4.9 GHz (still possible even after almost 4 years) with single channel RAM or shall I keep the 6500T with dual channel RAM?

The use case of the system will be like a secondary PC - Mainly for media consumption, some coding and light gaming (it has a Zotac 1660Ti AMP at present).

 

[oldwalltree]

Thanks for the response. I am still looking out for an used 7600K or a 7700K but these are really hard to find here for a decent price.
Coming to the real question now, what do you guys suggest? Shall I continue with my i5 7600K @ 4.9 GHz (still possible even after almost 4 years) with single channel RAM or shall I keep the 6500T with dual channel RAM?

The use case of the system will be like a secondary PC - Mainly for media consumption, some coding and light gaming (it has a Zotac 1660Ti AMP at present).

I would think the 7600k @ 4.9 with single channel would still beat the 6500T @ 4.4 with dual channel. But just run a few CPU benchmarks and that will for sure give the answer your looking for.

 

[DR4G00N]

Dual channel actually provides a significant performance boost over single depending on the application (especially for games).
As long as the programs you run don't rely on AVX the 6500T would probably be faster overall.

 

[oldwalltree]

Dual channel actually provides a significant performance boost over single depending on the application (especially for games).
As long as the programs you run don't rely on AVX the 6500T would probably be faster overall.

Agreed but I'm curious of the actual numbers with the 7600k as the faster overall chip and +500 on the clock speed if that would make up the difference compared to a lower clocked chip in dual. Post some benchmarks please!

 

[itsakjt]

Thank you everyone. Benchmarks coming up.

i5 7600K

OC Validation @4.9 GHz
Intel Core i5 7600K @ 4901.18 MHz - CPU-Z VALIDATOR (x86.fr)

Cinebench R20 Multithread - 1987 points

Update 1: Cyberpunk 2077 with the i5 7600K @ 4.9 GHz and the Galax RTX 2060 Super (+200 MHz core and +850 MHz memory) - Average around 75 FPS. CPU usage always at 100%. Stutters while on car with drop in GPU usage to as low as 72% and CPU usage at 100%.

i5 6500T:
CPU-Z Validation for 4.3 GHz (unfortunately, that is the maximum this chip stays stable at, needs a lot of voltage too but since TDP is low and I am using a liquid cooler and delidded the chip, removed that adhesive and applied CM Mastergel Maker, so temps hardly reach 75 degree C)

Yes it scores significantly lower in Cinebench. Even lower than a stock 7600K.

BUT, Cyberpunk runs better. Framerates are much more consistent. 75 is average but does not stutter as much as the faulty 7600K with single channel RAM. I didn't know dual channel was so important for Intel platforms. Everything feels snappier.

I put in my RTX 2060 Super to rule out any GPU bound issues as much as possible.

Memory read and write speeds on AIDA is almost twice in the 6500T than the 7600K.

This is not indicative of absolute performance of the overclocked 6500T. There can be certain AVX specific workloads that might perform better on the faulty 7600K but this works better for my use case and I am going to stick with the 6500T until I find an acceptable deal on an used 7600K/7700K.

Cheers all.