What is Uncore? How is it relevant to overclocking?
I'm new to overclocking and I'm having trouble understanding what I should be setting my uncore to.
Uncore frequency is the frequency of the non-core parts of the CPU, ie cache, memory controller, etc. It's also known as ringbus frequency.
Opinions are somewhat divided on how much effect it has on overall performance (if any). What is certain is that it's completely pointless to set uncore frequency above core frequency.
I'd recommend getting your core up as far as you can without touching uncore. When you're done, up uncore to as close as you can get it to core frequency. Don't sacrifice core frequency for uncore frequency.
leeashton said:the best picked answer here is wrong, uncore is the disabling of the core in the registry!
What you're thinking of is core parking I believe. Uncore is definitely the non-core parts of the CPU.
Ideally the Uncore ratio should be the same as the core ratio (as it is at stock values) or (particularly in the case of overclocking) higher than the clock ratio to not constitute a bottleneck. On my Intel i5 6600K I set the Core at 46 (4.6 GHz) and the Uncore at 49 (4.9 GHz) - yes, much higher than the Core! I tested it stable on a 2H Prime95 Blend test up to Uncore 52 and could probably go beyond that value but the overall performance drops after 49, so that's what I use.
To measure performance I measure the time it takes for the system to complete the Prime95 800K test on the four workers. Setting the Uncore ratio at 49 rather than 40 shortens the time by some 7 minutes (from 48 min. to 41 min.). Getting 7 minutes shaved off on 48 is getting 14.5% of raw processing (computational) performance gain! It does not change the Temp. and Power significantly from 40 to 49 (topping at 84 C max under 26 C ambient and 104.5 W) although I had to up VCore from 1.355 V to 1.390 V to ensure stability. The stability of the PC (BSODs, hanging, etc.) is also much greater, in fact rock solid (never had any trouble ever since). It is so good that I really feel it.
Games that would usually get the 4 cores at (for example) 98-96-100-97%, now leave them at 83-87-93-84%, further showing the overall gain in CPU performance. THIS IS ABSOLUTELY FANTASTIC !!!