FEATURE/ ANALYSIS
CPU CLOCK SPEED
Having established a sweet spot for gaming performance around the
6-core mark, we next wanted to test the effect of clock speed. The opinion
has long been held that Intel CPUs are still the best for games, as they have
a clock speed advantage, although AMD has closed that gap considerably
with the latest Zen 2 Ryzen processors.
To test just where CPU clock speed sits in the hierarchy of importance for
game speed, we took our results for the 8-core test, then compared them
with the CPU underclocked to 3GHz and then overclocked to 4.2GHz. The
results were conclusive.
Right across the board, as soon as we downclocked our CPU to 3GHz,
performance dropped. Even in ROTTR, where the number of CPU cores
made little difference, there was a noticeable drop in frame rate at 1080p.
That said, in most instances, it wasn’t as big a drop as we expected. After all,
this is a CPU with a base clock speed of 3.6GHz and a boost clock speed of
4.4GHz, so forcing it back down to just 3GHz is quite a drop.
Meanwhile, giving our CPU an all-core overclock proved more of a mixed
bag. In some instances, we saw a clear increase in performance, such as in
Dota 2 and PUBG at 1080p. However, in others, there were minimal gains
over the stock clock speed. A large part of this is down to the fact that AMD
Ryzen CPUs tend not to overclock easily above their default boost clock
speed, as was the case with us hitting 4.2GHz, when its boost clock is 4.4GHz.
However, that boost clock only applies to one core and isn’t guaranteed,
whereas an all-core overclock is always on. As such, those games that can
limit their CPU usage to just one core can get the full boost clock advantage,
but where more cores are involved, the overclocked CPU takes the lead.
That’s why the likes of Dota 2 saw big gains with the all-core overclock,
whereas CS:GO or PUBG saw little to no improvement.
ESSENTIAL
Our tests show that a quad-core CPU is the minimum for a decent gaming
PC these days, but you don’t have to go much higher to maximise your
gaming performance – six will probably do for most users. As for clock
speed, the more the better, but any chip that can hit around 4GHz will have
enough power to put the focus back on a graphics card upgrade. The
6-core Ryzen 5 3600X is a great option, or alternatively, the 6-core Intel
Core i5-9600KF is a decent gaming choice for under £200.
MIDRANGE
Having established that clock speed is still a major factor in PC gaming
speed, and that there’s not a huge advantage in having more than six cores,
any of AMD or Intel’s processors with six or eight cores will be fine for a mid-
range gaming system, especially if you get overclocking. The £300 Ryzen 7
3700X is a great choice here, as is Intel’s £340 Core i7-9700K.TOP DOG
AMD and Intel reserve their fastest clock speeds for their flagship
processors, so if you want to maximise clock speed (without overclocking,
at least), you’ll have to stump up the cash for the AMD Ryzen 9 3950X or
Intel Core i9-9900K. You won’t see much benefit from all the extra cores
on the former, but that clock speed will pay dividends. Alternatively, you
couldjustoverclockcheaperoptionswithfewercores.CPU clock speed (average fps)
1,920 x 1,080 3GHz 3.6GHz 4.2GHz
Rise of the Tomb Raider 118 123 124PUBG 144 165 168
Dota 2 163 179 185
Ashes of the Singularity 46 54 55CS:GO 172 197 2103,840 x 2,160 3GHz 3.6GHz 4.2GHz
Rise of the Tomb Raider 48 48 48
PUBG 65 73 70
Dota 2 136 139 137
Ashes of the Singularity 45 53 54CS:GO 166 195 189A 6-core CPU, such as AMD’s
Ryzen 5 3600X, will be fine for
most gaming needsIntel’s Core i9-9900K
and 9900KS are the clock
speed kings at the moment,
with the latter boosting to
5GHz on all cores