Trying to decide between i7-8700K and i9-7900X (Meltdown and Spectre issues)

[modeonoff]

Hello, I need to build a powerful workstation for professional research work. I planned to build a high-end workstation using the i9-7900X but I am concerned about potential performance lost due to Meltdown and Sprectre. My work involves computationally intensive simulations that involves CUDA computations using multiple high-end GPUs. From another thread, I read a -20% performance drop. That is a lot. I know all CPUs are affected. Does the 8700K also suffers from such big performance lost? I don't mind paying for the 7900X as it is work related. However, if the performance drop is so much, I wonder if I should go ahead to buy the components to build the i9-7900X system or just build a i7-8700K system which is $1000 less.

https://linustechtips.com/main/topic/882509-intel-vs-am...

 

I will use Ubuntu Linux on this workstation most of the time.

 

Any advice appreciated. Thanks.
 

[themctipers]

The performance loss is negligible (3-5% possibly, maybe) on newer architectures and the older ones have a larger performance hit, ~20% or so as you say at max (maybe core 2 duo era?)

 

if it just requires CUDA, go for the i9 that has more PCIe lanes (more PCIe lanes, more GPUs can be used for compute, 8700k only has 16 lanes)

[modeonoff]

Thanks. I know that the 8700K has only 16 lanes. That is why I chose the 7900X originally. If I go for the 8700K, it will be just a temporary system until PCIe 4.0 components come out in about a year. I will then just change the motherboard and CPU.