Cache size impact on gaming

DELTAprime · February 8, 2017

Assuming that the leak of the 7640k is real and it will be a 4C/8T i5 CPU with 6mb of cache as opposed to the i7's that have 8mb of cache, how much of a performance decrease would be seen in CPU intensive games like Watch Dogs 2 and AOTS by having 2mb less of cache?

Lethalmonk · February 8, 2017

To put it in short. Almost nothing.. maybe itll have a VERY small difference but nothing you can tell for gaming. Video rendereing etc will have a greater difference.

ARikozuM · February 8, 2017

More cache is better since the calculations done on a CPU's L3/L2 are much faster than RAM. HT doesn't help as many games, unless they can use the logical cores fully rather than a few, but more cache will almost always equate to better performance.

Obligatory Minesweeper at 288Hz! What a time to be alive!

fjdhdhcyfhf · February 8, 2017

its huge. its 3/4 the amount of cache in the i7. that means more cpu cycles used to get instructions and data from RAM. We dont however know the speed difference in these cache, i imagine the newer chips will have faster cache

Mira Yurizaki · February 8, 2017

I would argue cache affecting performance largely depends on its architecture as well. During the Athlon XP vs. Pentium 4 days, the Athlon XP was able to go toe-to-toe with the larger cache equipped Pentium. In an inverse of this, Sandy Bridge only had 256KB of L2 cache per core, whereas Bulldozer has 2MB of L2 cache per module (or 2MB shared per two integer cores).

Cache also takes up a lot of real-estate on the CPU die. For example here's Haswell's die:

Including just the cores and L3 cache, cache takes up roughly a third of the die space.

If you're talking about cache sizes within the same architecture, generally more is better. But between architectures, it's up in the air.

MageTank · February 9, 2017

You can test this with current i7's. Enabling the iGPU cuts off 2mb of usable cache (even if you are using your dGPU). I've done this test before, but saw no differences in average framerates or any perceivable stutters. HT on the other hand, tends to help with minimum framerates quite a bit depending on the title. Fallout 4 and Far Cry 4 are great examples of this.