https://www.extremetech.com/computing/amd-ryzen-9000-cpus-run-7c-lower-than-zen-4 This generation of high-end CPUs has pitted AMD's Zen 4 7000-series against Intel's Raptor Lake CPUs. In that conflagration, only the Intel CPUs have gained a reputation for running hot, but AMD's chips weren't exactly frosty in comparison. AMD's high-end Zen 4 chips were known to zoom immediately to 95C when put under full load, and our sister site PCMag's only "negatives" listed in the Ryzen 9 7950X review were that it was an "energy hog" and it "runs hot." AMD has apparently taken this feedback to heart for Zen 5 and is now saying it's been able to reduce CPU temps by 7C compared with Zen 4, though your mileage may vary.
AMD is building up hype for the launch of the first Zen 5 CPUs, which it now says is occurring on July 31, so check your credit card balance now. As part of the pre-launch campaign, it released some marketing slides discussing its full CPU lineup and its benefits compared with Zen 4 and Intel's Raptor Lake CPUs. The one that caught our eye is the thermal improvements, which AMD says is "up to" 7C at the same TDP. This comparison was made using a Ryzen 9 9950X and a Ryzen 9 7950X with a 240mm AIO running Cinebench, so it seems like a pretty straightforward comparison.
AMD's marketing slides don't mention how these thermal improvements were achieved. However, according to club386.com, the company used a new thermal interface material (TIM). It minimized hotspots by changing the layout of the dies on the package, which was previously a bit of an issue since these 16-core CPUs generated a lot of heat at the top of the chip where the two compute chiplets are located. Looking at photos of a delidded dual-CCD chip provided by AMD (above), it's hard to spot the differences in the layout, so we'll be curious to see actual thermal benchmarks on or around the 31st.
There are two reasons AMD's high-end Zen 4 CPUs ran so hot. The first is that modern CPU cooler design has been relatively unchanged from the early days of CPUs, with a monolithic die dead-center on the package. AMD's chiplet approach, which started with Zen 2, changed this calculus due to the location of the heat-generating components being off-center. Some cooler companies have even begun offering kits to shift the contact patch up a few millimeters to deal with it.
The other reason these chips can run hot is that AMD says it designed them to run this way to achieve maximum performance and that even 95C was within spec. This may be true, but most temp-watching PC enthusiasts don't like it when their CPU is above 90C, as it typically causes a lot of fan noise, and it feels like it could shorten the CPU's lifespan. If AMD has been able to get those temps down to the high 80s, that's certainly an improvement, but still not perfect. However, for Zen 5, only the flagship Ryzen 9 9950X is a 170W TDP part, with the 9900X (12-core) being 120W and the 9700X and 9600X being just 65W, so it seems plausible most of the Zen 5 chips will run quite cool. We'll find out in just a few weeks.
I'm buying one as soon as they are available.