I'd like to first apologize for the long post, i did try to keep it short....
Greetings. I've been doing some research on AMD's Mantle and all i could find was frame rates comparisons.
I decided to post my personal feelings after playing Battlefield 4 with Mantle so that people interested in frame times and input lag can have more information when buying a GPU. Please feel free to post your experience with this api as i'm sure most of you have tested it. As a side note i'd like to mention i'm not a big fan of BF or CoD or any modern shooter for that matter.
My rig.
Athlon II x3 450 ->unlocked and overclocked to Phenom II x4 B50 @ 3.55Ghz stable for years.
4 GB 1333 ddr3 cl9 ram (2x2)
MSI gaming 3g R9 280x OC edition @ 1100 / 1500
Even though i meet the requirements to play BF4 the gameplay using directx11 is horrible. I'm sort of an input lag freak, i can feel it even when its barely there and i can't stand it. I feel like ever since the arrival of compute cores on GPUs games have been suffering from a combination of input lag and stuttering and a lot of people seem to agree including John Carmack. I've tested games on a lot of systems and they seem to lack the responsiveness of Quake3 running on an old school card like a Geforce 3Ti for example. This has caused me to give up playing shooters or fast paced games on the PC and instead focus on MOBA games on spare time.
Now that thats out of the way lets get down to mantle. While i was getting playable frame rates with the above rig using directx11 (i didn't see it go under 30 and it was mostly 45-50) the stuttering and the input lag made the game feel uninteresting, immersion was nonexistent. The reason behind my pairing the r9 280x with an old slow cpu was because i wanted to see how much boost it got from Mantle. And i was AMAZED not only did my fps rise but the stuttering and input lag EVAPORATED, i felt like i was playing Call of duty 2 @ 300fps even though i was only running at about 60. I've not seen a game play this smooth and have such great responsiveness at 60 fps and i guess i wanted to show my enthusiasm and also help those who have doubts about Mantle.
Before anybody starts saying i'm an AMD fanboy i'd like to point out that i had more nvidia cards than amd ones and nvidia does shine in areas where amd has a long way to go. That said i personally thing AMD nailed it with Mantle; this is how games should play!
well that's if Mantle actually kicks off, right now we don't know what Direct X12 will do, some rumors state it will have the same benefits as mantle, so the only way the only way mantle will kick off is that if DirectX12 fails to address what Mantle has fixed. which we don't know when it is coming. if DirectX12 Does fix everything then Mantle will be "Dead on Arrival" and i mean that since there is about 4 games that support mantle.
Its a win/win, if DX12 doesn't fix it Mantle will take off, If it does fix it then its good either way. The thing the bothers me is that M$ had plenty of time to fix it, they just didn't care so i kinda hope dx12 fails so that next time they will try to innovate rather than just pump out the same garbage with their overpriced OS.
I doubt you can notice input lag on a blind test from a Geforce 3 and say a gtx 650 in quake 3. I do feel like some of the new cards have something missing, this and the fact that most cheap lcd's just can't compete with the old CRTs make me feel nostalgic. So maybe it's just that and not an actual tangible difference.
Frame times are not that big of a deal if you don't know or care about them, nocebo works even in games.
Also it's a matter of adaptation. You can get used to high input lag after enough time, but takes practice and time.However, I can immediately notice a difference between my old Samsung pannel rated 10ms and a new one in a Dell at 6ms, the first feeling more like 64ms, with noticable lag in Windows, dragging the mouse around.
also this may be a problem but Mantle only seems to be a benefit on Low-End Hardware. Using a R9-290x and a Mantle Supported game has almost no benefit. with only about 2 or 3 fps gain. so maybe that is an issue or the games. or there may be a tiny problem with mantle.
I don't care about fps gain. I want smoothness and responsiveness.This is like nvidia g-sync, hard to explain but you immediately understand it once you see it. Btw the biggest gains are with weak cpus that people still use.
@TropiKo if you cap the game at say 100fps you can feel the 650 has more input lag, if you don't cap the fps the stronger 650 compensates with higher fps.
Btw i've tried playing CS 1.5 with a GTS 450. The game is capped at 100 and the input lag at 100fps was terrible. This was for a friend who loved the old school CS and wanted to play it for old times sake with some friends. I tried drivers, settings, rivatuner and couldn't fix it, it was unplayable. So fps does matter up to a point but there are other things that should be taken into consideration unless you play turn based strategy.