i9-9900K problems re-release

I decided to rewrite post about i9-9900K to put all old and new discoveries in one post, so it will be easier to find and read.

i9-9900K is 8 core CPU with enabled hyper threading giving us 16 logical CPU’s. It was 95W TDP, base frequency 3.6 GHZ and Max Boost 5.0 GHZ. It cost about $529 USD.

If you compare specs with previous top 8700K you will see that there are 2 more cores (give plus 4 logical CPU’s), additional 0.1 GHZ base frequency and 0.3GHZ additional Max Boost frequency. It also has 0.5 MB L2 cache and 4 MB extra L3 cache. But guess what? Tech process and TDP didn’t change. Moreover, there were no big changes in CPU design. So how Intel achieved this? Very simple. By lying to all of us. Let me explain how they did it.

All of us seen signs “Up to 90% off”. I think “cool, good discount” and you go to that store. And then you realized that while technically it is true it is not true at the same time. If you come inside, sure, there will be some item that is 90% off. But most of other items will be discounted much less and high chance that items you are interesting in will not be discounted at all.

In Intel case you CPU have will have 95W TDP OR 5.0 GHz Boost. And let me explain in detail how does it happens because it is quite tricky.

First thing I want to mention that Intel has spec, how motherboard should control power, boost etc. By controlling it correctly motherboard will keep CPU within 95W TDP. But most motherboard don’t follow spec, or don’t do it by default because then CPU perform much slower. With 95W TDP it performs about same as AMD 2700X that cost $289. And if you don’t believe me, here are full review https://www.youtube.com/watch?v=kmAWqyHdebI.

As result, many reviewers believe that by Intel’s blessings most vendors allow much longer boosts and for more cores at the same time. As result much higher performance but TDP will grow much higher as well. In extreme cases on MSI God like, CPU consumes little bit less than 200W (without overclocking). Yes, performance boost is appropriate but cooling off 200W is quite different from cooling off 95W. And that board cost $584 which is more than CPU itself. TDP with all other motherboards is about 150W.

By now you probably realized that new CPU is can be quite power hungry. Moreover, what’s new in that CPU that it able to detect lack of power from VRM and decrease its frequency. As results you can buy not that expensive motherboard (less than $200) that supports i9-9900K and CPU will stay at 3.6 GHZ and never boost at all because that motherboard not able to provide enough power. There are many reviews and tests where mosfets on motherboard easily go over 100 degrees Celsius without any overclocking. Also, you can buy good motherboard, but your cooling is not optimal, and result could be the same as close to that. For example, you can buy expensive liquid cooling solution for CPU but due to lack of air around CPU mosfets will overheat and CPU will throttle down.

As the bottom line, new CPU is fast, but it requires good motherboard that must be carefully chosen, and it requires good cooling. So just CPU, motherboard and cooling will cost as whole computer. And it is not that much faster as it is expensive.