Uncommon Core i9-9900T requires no active cooling, offers similar multi-thread performance to the Core i7-9750H

When compared to the hexa-core 9th gen Core i7 series, the octa-core 9th gen Core i9 series is able to offer superior multi-thread performance. However, can a passively-cooled Core i9 SKU maintain its performance advantage over a standard Core i7?

We recently had the chance to test a completely silent mini PC with a passively cooled 35 W Core i9-9900T to see how the processor would hold up with no fans at all. It's an appealing concept considering the form factor and CPU involved, but Impact Display Solutions has pulled it off... for the most part. CineBench scores are within 3 to 6 percent of the average Core i7-9750H CPU taken from over 50 laptops in our database. It should be noted that an octa-core CPU cannot be directly compared to a hexa-core CPU in this manner, though the results are interesting nonetheless.

The problem arises when the Core i9-9900T is stressed for long periods. As shown by our CineBench R15 Multi-Thread loop test below, clock rates nose dive toward the latter half of the stress test for a significantly lower score of only about 350 points. Performance eventually recovers until a certain temperature threshold is reached again to repeat the process. A deeper look with HWiNFO shows clock rates falling from 2.6 GHz to just 300 MHz in order to keep core temperatures in check. Thus, a passively-cooled Core i9-9900T is only able to stand toe-to-toe with an actively-cooled Core i7-9750H temporarily.

We imagine that an actively-cooled Core i9-9900T PC wouldn't exhibit the same throttling issues as mentioned here. Few commercial PCs carry the uncommon Core i9-9900T as mini PC form factors generally prefer to use 45 W Core H-series CPUs or 65 W desktop Core i7 CPUs instead.

See our review on the Impact Display Solutions mini PC for more performance details on the Core i9-9900T.