Is a CPU with more than eight cores really necessary for gaming? Most likely not. However, the new 12-core AMD Ryzen 9 7900 is still very alluring.
The price has significantly changed from the Ryzen 9 7900X 12-core model. The new 12-core-lite Ryzen 7 7900 non-X listed for just $456 (opens in new tab), while the full-fat “X” chip costs $549 as a monster. We’ll see that it’s not really so “lite” after all.
However, that cost warrants a little bit more consideration. The Ryzen 7 7700X costs $399, while the Ryzen 7 7700 (opens in new tab), the other new non-X variant, costs $329. Therefore, you are paying a very small premium over the 7700X for the additional cores.
You receive 50% more cores for only 30% more money as compared to the non-X 7700. This isn’t how it’s meant to operate, is it? Typically, the value proposition gets worse as you move up the CPU or GPU spectrum. however not here. These new Ryzen 7000-series non-X CPUs are undisputed champions of value.
AMD Ryzen 9 7900 Specifications & Overview
AMD’s clock-speed and power paradigms were only minimally altered with the introduction of its “Zen 4” architecture. Historically, CPUs have had a thermal limit that, in a perfect world, you wouldn’t want the CPU to approach.
However, today’s CPUs are made to function regularly at or even close to their thermal limit. Even with a 240mm water cooler, the majority of the Ryzen 7000 Series processors we have tested thus far have reached their thermal limits under heavy load, and after doing so, they throttle back to keep their temperatures from rising further.
The CPU tries to obtain as much performance as it can within its temperature constraints, which is somewhat of a “maximum performance at all costs” strategy. This has resulted in a significantly greater power demand, which is why coolers are not included in the box with AMD’s CPUs that end in “X”.
An inexpensive stock cooler cannot withstand the heat generated by chips drawing up to 230W from the CPU socket. It’s not a major issue, though, as these CPUs are primarily designed for the high-performance enthusiast population, which already primarily employs aftermarket coolers.
AMD has created lower-power versions of its existing CPUs, which are identified by the lack of an X at the end of the product name, if you don’t want your desktop to serve as a space heater. The electrical diet for these non-X variations is rather stringent.
The 7900X features a 230W maximum socket demand and a 170W thermal design power (TDP). The AMD Ryzen 9 7900 has the same 65W TDP and 88W socket draw as the AMD Ryzen 7 7700, consuming only a third of that amount.
For the 7900, however, who has four more cores to support than the 7700, this might be more of a constraint. The basic clock rate has been reduced from 4.7GHz on the 7900X to 3.7GHz in order to account for the lower power consumption. From 5.6GHz to 5.4GHz, the maximum boost frequency is likewise decreased.
The Ryzen 7000X and non-X CPUs are identical in terms of hardware, just as the prior Ryzen generation. The two-CCD chiplet design of the AMD Ryzen 9 7900 and 7900X uses an Infinity Fabric interface to join them. There are eight cores total on each CCD, with two of them being disabled. As a result, the CPU has 12 cores and 24 threads. Each core features a 64K L1 cache, a 1MB L2 cache, and a shared 64MB L3 cache amongst all 12 cores.
AMD’s Wraith Prism cooler is the one that is provided. It’s a fairly capable unit for a stock cooler. In comparison to all aluminum designs, a copper contact slug and heat pipes offer superior heat transfer. Because of the fin stack’s size and density, the cooler can handle processors with a 105W TDP.
It also offers configurable RGB lighting for a dash of style. It should also offer significantly greater airflow and cooling over the RAM and VRMs of whatever motherboard it is used with because it is a downdraft cooler rather than the more typical tower coolers.
AMD Ryzen 9 7900 General Information
|Regional Availability||Global, China, NA, EMEA, APJ, LATAM|
|Product Line||AMD Ryzen™ 9 Processors|
|Max. Boost Clock||Up to 5.4GHz|
|Processor Technology for CPU Cores||TSMC 5nm FinFET|
|Thermal Solution (PIB)||AMD Wraith Prism|
|# of CPU Cores||12|
|Unlocked for Overclocking||Yes|
|Product Family||AMD Ryzen™ Processors|
|# of Threads||24|
|Max. Operating Temperature (Tjmax)||95°C|
AMD Ryzen 9 7900 Performance & Tests
On our upgraded AMD AM5 test rig, AMD’s Ryzen 9 7900 was benchmarked. The test platform is an ASRock X670E Taichi motherboard with 32GB of DDR5 memory running at the highest RAM frequency that the CPU can support (DDR5-5200).
A Cooler Master PL240 Flux all-in-one liquid cooler controls the CPU cooling, and an Nvidia GeForce RTX 3080 Founders Edition delivers discrete graphics power. The SilverStone DA850 power supply is in charge of providing power to the entire system, which is installed on a Praxis Wetbench open-frame PC case.
L1 and L2 cache rates lagged the 7900X chip by no more than 5%. The Ryzen 9 7900’s read rate dropped to 10% behind the 7900X in the L3 bandwidth, while the L3 write was about 30% slower and only marginally quicker than the Ryzen 7 7700 models.
Unexpectedly, the AMD Ryzen 9 7900 and 7900X shared first place in the Adobe Premiere benchmark. This serves as a crucial reminder that not all execution threads are created equal. For instance, AVX instructions frequently consume a lot of power and produce a lot of heat.
It seems the Ryzen 9 7900X produced too much heat during this job and reduced its clock speed as a result, perhaps because to its greater voltage and power usage. In this benchmark, the AMD Ryzen 9 7900 was able to match the 7900X frequency despite operating on a substantially lower power curve while using the same cooler.
AMD Ryzen 9 7900 Conclusion
So, the Intel choice is not a sure thing. You can argue in favor of AMD, particularly if you are concerned about power usage. The AMD Ryzen 9 7900 is significantly more efficient than the Intel alternative at stock settings.
As a result, you pay your money and make your selection. The Intel choice likely makes more sense for the majority of gamers, most of the time. However, this new low-power approach from AMD results in the most attractive Zen 4-based CPU to date.
AMD Ryzen 9 7900