This morning the patch for BF4 that enables mantle went live. Mantle has been in development at AMD for a while now. The whole idea behind mantle was to enable a more efficient way for the game programmer to use the graphics card. In other words frame rates should increase. What we didn’t know was that it was primarily going to help with CPU limited situations.
There are two schools of thought on cpu throttling in games. One is that with a modern CPU you are almost never CPU limited in gaming. The other is that for 120Hz or lightboost type setups that you are almost always limited by CPU. Both are true, the former group only thinks about single player games at 60 frames per second. However a game that can have 64 players and buildings blowing up along with very detailed graphics can often be limiting to a CPU when it’s also trying to pump out a high frame rate. This can be particularly frustrating if you have a CPU with a large count of cores or threads because very few games are good at using more than a few cores.
So who will benefit from Mantle? The quick answer is anyone with an “abnormally” good GPU setup relative to the CPU. I.E. Someone who has an old computer but upgraded the graphics card to something quite new and good. The other people to benefit are the very high end multi GPU users. I.E. The guys who despite having the latest and greatest CPU are still trying to hit 120FPS minimums reliably.
Who won’t benefit from Mantle? The quick answer is anyone with a cheap GPU and a high end CPU. For example an overclocked 4770K paired with a R7-260x is unlikely to see much of a benefit.
In the BF4 blog, the BF4 developers show the effect based on three different systems and scenarios. The first is low end CPU/GPU single player which showed a 14% gain in FPS, the second was a medium to high end CPU/GPU multiplayer that showed 25% improvement in FPS, and the last was a 3970x with dual 290 cards that showed a whopping 58% increase in frame rate from 78 to 122fps. Now bear in mind the 3970x was not overclocked and that their situations were cherry picked, but we know that 120FPS is often a struggle and you can see that in some of the SLI/CFX scaling benchmarks where scaling can work well as long as FPS is <70FPS, but scaling starts to seem pretty horribe when the 3rd/4th card is giving numbers above 100FPS. Obviously these numbers are going to a bit cherry picked. We'll have to see just how much the real end users see a difference in day to day use though. Oh and before you run off and get disheartened that not everything works properly just yet - the 14.1 drivers are still beta and it doesn't work with some cards such as the 7970/280x and multi GPU setups may be prone to stuttering. For a long time many PC games have been poorly ported console versions and developers have been happy as long as a high end PC can manage 60FPS even if with more work it could do more. Hopefully Mantle will give developers an easier path to give us a more efficient games with higher frame rates.