Not prime related, but Cinebench seems to be a popular CPU benchmarking application so I thought it would be interesting to try and understand how it behaves.
Ram influence: On the 6700k system dual channel 3200 to single channel 2133 only varied scores 1.5% or so. So ram performance doesn't significantly impact things much here, unless you're competitive benching.
Hyper-threading - how much does it help? On Skylake, I saw 31% boost for on vs off with 4 cores, or 28% if you normalise to 1 core. Haswell was similar with 33% and 28% respectively although I'm using an i3 and i5 here. For Sandy Bridge i7 mobile 29% and 19% respectively.
Skylake cache - putting aside HT, does having 8MB of L3 cache on the i7 help over 6MB cache on i5? Nope. Results were practically identical.
Generational differences: Based on 1 thread results as least limiting by other factors, Skylake is about 7.4% faster than Broadwell. Broadwell is about 3.9% faster than Haswell. Haswell is about 8.5% faster than Sandy Bridge.
Still with 1 thread results, it does seem to normalise well with the following as points per CPU GHz:
Skylake 43.9 (56.1 with HT)
Haswell 39.3 (50.3 with HT)
Sandy Bridge 36.3 (43.2 with HT)
This could also be multiplied up to predict where multi-core scores end up, but this wont take into consideration less than perfect scaling.
On two systems (Skylake, Broadwell) with Windows 7 and and Intel integrated graphics, I saw Cinebench use up a ton of CPU even when the benchmark wasn't running. This crippled results, and the effect disappeared after I installed a separate GPU. However a Sandy Bridge system didn't show this, nor did a Haswell Win10 system. I didn't dig into this further.
i7-6700k 4.0 GHz, 3000 dual channel dual rank
i7-6700k 4.2 GHz, 3200 dual channel dual rank
i5-6600k 3.6-4.0 GHz, 3000 dual channel single rank
i5-5670C 3.5 GHz, 1600 dual channel dual rank
i5-4570S 3.2-3.5 GHz, 1600 dual channel dual rank
i3-4150T 3.0 GHz, 1600 dual channel single rank
i7-2620M 3.2-3.4 GHz, probably 1333 dual channel but can't be sure
To check my results, I did look at some user submitted benchmark results elsewhere. It seemed to work well for Skylake and Haswell, with some user scores even higher than I predicted. I should add, the more serious benchers will tweak the software in their system so nothing else gets in the way. I didn't do that, so they gain a bit there.