Questions on the Benefits of X299 7900x vs 7700K SLI

[Sam_269]

Hello all,

I have done some research on this and looked at some benchmarks but I cannot find an answer that considers all the factors below.

My system is the following:
CPU: i7 7700k (OC to 4.9)
Motherboard: ASUS Z270E Gaming
RAM: Corsair Vengeance 3200 (Could only get it up to 2933 without errors on this system)
GPU: 2 x ASUS GTX 1080 (OC to 2100)
HDD: m.2 NVME Plextor 1tb
Power supply: Corsair 850 watts
Monitor: 3440 x 1440 100Hz

My question is considering the improvements in SLI and NVME and higher clocks on the RAM how much of an improvement is a X299 7900x (OC to 4.5) system for a gaming mostly system? (not considering the price, I know it's a waste as a gaming system)

I am quite new to the PC masters race so I appreciate all your opinions.

Thanks,

 

[TwilightRavens]

The main difference would be PCI-E lanes, so basically more bandwidth for multiple GPU's. Aside from having more than 4 cores. You'll not notice much difference in fps in games according to benchmarks, the 7900x actually scores lower in games than your 7700K

 

[Sam_269]

The main difference would be PCI-E lanes, so basically more bandwidth for multiple GPU's. Aside from having more than 4 cores.

I've seen a bunch of benchmarks saying that 16x 16x vs 8x 8x is a small improvement. But they all test on the same clock speed. This comparison would be between 16x 16x at 4.5 OC vs 8x 8x at 4.9 ~5.0 OC. Also in this system there is also a NVME system using 4x.

So basically I am wondering since my CPU has only 16 PCI-E lanes and I have two GPUs and an NVME drive is my system becoming more like 8x 4x 4x?


So thats why I am wondering if there is any gain.

 

[k1114]

Cpu speed isn't going to make the gpus use more pcie bandwidth. They won't care about being 8/8 and the higher oc will get more fps. Ram speed isn't going to matter. M.2 uses chipset lanes not cpu so you are still 8/8. You won't see any improvement, actually it'll be worse since the extra cores won't matter.

 

[TwilightRavens]

The main difference would be PCI-E lanes, so basically more bandwidth for multiple GPU's. Aside from having more than 4 cores.

I've seen a bunch of benchmarks saying that 16x 16x vs 8x 8x is a small improvement. But they all test on the same clock speed. This comparison would be between 16x 16x at 4.5 OC vs 8x 8x at 4.9 ~5.0 OC. Also in this system there is also a NVME system using 4x.

So basically I am wondering since my CPU has only 16 PCI-E lanes and I have two GPUs and an NVME drive is my system becoming more like 8x 4x 4x?


So thats why I am wondering if there is any gain.

98% of games currently on the market are not optimized to use that much bandwidth, you would see little to no performance benefit from that and in some cases a reduction.

 

[Sam_269]

There also seems to be a lot issues with X299 and SLI

http://www.tomshardware.co.uk/forum/id-3470275/x299-sli-gtx-1080-performance-problems.html

 

[mtoddvan]

http://www.userbenchmark.com/PCBuilder

 

[k1114]

Kaby and sky lake do not have any difference in ipc. Clock for clock it is the same.

 

[TwilightRavens]

Cpu speed isn't going to make the gpus use more pcie bandwidth. They won't care about being 8/8 and the higher oc will get more fps. Ram speed isn't going to matter. M.2 uses chipset lanes not cpu so you are still 8/8. You won't see any improvement, actually it'll be worse since the extra cores won't matter.

^ couldn't have said it better myself

 

[Sam_269]

thanks for the great answers peeps.

 

[mdd1963]

Every day or so, I see someone assemble a 6900/6950 on X99 because they plan on SLI, (watch Linus ooze praise onto some recent min-build within last 24 hours) despite the testing showing that such rigs are still ....well....slower than Z270 when running single card or SLI.....

I shudder to even think about X299 SLI results, but, can only imagine that they'd likely be even worse...

Results matter.