AMD Ryzen 9 7900X processor review

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Conclusion

Final Words 

We do not expect the Ryzen 9 7900X in specific to be the best-selling product from AMD, is a bit of an odd one with that weird core configuration. But we do think it offers tremendous performance. With the current PPT setting at 175W, the temperatures are manageable as long as you have LCS.  $549 bucks for a twelve-core processor is a little steep, and in the EU you need to add your country taxes as well. At 21% you'll be looking at 849 EUR (!) So if you purchase this processor, you must be very sure you need and utilize all cores; otherwise, it's just money wasted. With energy costs soaring, it has never been more essential to examine the power consumption of your computer, both when idle and under load. Given the performance capabilities of the AMD Ryzen 9 7900X processor, it comes as no surprise that it consumes quite a bit of energy.  The 7600X and this 7900X seem to perform better in thermals.  After examining it, it seems that our ASUS board's latest firmware is no longer configured at a PPT (maximum wattage of 230W, we see a ~175W limit. We still get close to 90 Degrees C under load though. We hit sub-90 degrees C under massive load with a fairly typical LCS (admittedly, not the greatest performing one). AMD describes the Ryzen 9 7900X as having a boost of (up to) 5.6 GHz; however if you can cool the device better, you may achieve a better peak boost based on a Tjmax of 95°C. With our (modest) 280mm LCS, we got 5.70 GHz. But let's break things up.

Price and value

Another point to consider is the high (total) cost of ownership due to the requirement of upgrading to a new platform and DDR5 memory. The price premium for Series 7000 processors is a little icky; it does differentiate and isn't cannibalizing the current Ryzen 5000 series, I guess. You can purchase (we hope) the 7900X at $549,- and please do understand that if it is priced higher, wait until prices settle when there is good volume availability. For this Ryzen, you're paying 46 USD per core. You need to add to that the cost of ownership for the entire ecosystem and add DDR5 and a new AM5 motherboard. For the EU things get worse, expect roughly 849 EUR after taxes and that's 71 EUR per core. If you like to shave off some cost, I strongly recommend you wait a little more to see what the B650 series motherboards will have to offer as really, the differential will be more USB/SATA only. The infrastructure offered by these boards remains excellent unless you need dozens of USB ports and perse want PCIe gen 5.0 graphics slots. You should also remember that Intel has not yet released Raptor Lake (at the time of writing this article). 

 
USD SRP (ex TAX) GBP (Inc Tax) EUR (Inc Tax)
AMD Model 20% TAX 21% TAX
Ryzen 7000 Series AMD Ryzen 9 7950X $699 739.99 849.00
AMD Ryzen 9 7900X $549 579.99 669.00
AMD Ryzen 7 7700X $399 419.99 489.00
AMD Ryzen 5 7600X $299 319.99 365.00

Gaming performance

The new architecture and high clock rates help AMD get back in the saddle compared to Intels' 12th Gen products, but Intel is about to release 13th Gen products. Although (compared to 12th Gen Alder Lake) both have some wins and losses. It's now so close that individual wins per brand and processor segmentation (mainstream, high-end, and enthusiast) are accurate. So that means that this processor, on average, can feed frames as fast as Intel's equivalent with a mighty graphics card. Realistically though at six or eight cores, your gaming experience will be great; we feel that eight cores are the norm these days for a properly nice gaming PC and overall PC desktop. In the end, this twelve-core proc offers plenty of performance even to feed a GeForce RTX 3090. 

DDR5 Memory

The elephant in the room for Ryzen Series 7000 is the cost of ownership. While DDR5 memory will get cheaper next year, you'll likely pay a price premium right now. AMD indicates that 6000 MHz is a sweet spot, but please do read our scaling article for memory, as 5200 MHz isn't performing poorly either. The kit we received contained 2x 16GB G.Skill memory rated 6000:CL30. With this frequency and latency, the sweet spot will not be the price, with the ~300 USD you'll need to spend for this 32 GB kit. EXPO memory; it ran great; we tested the TridentZ5 NEO kit on an MSI, ASRock and ASUS motherboard. Once we had the latest BIOS up and running, would POST fast enough. The first time you startup the PC the BIOS will do memory training; this can take a few minutes. Once you move the BIOS to EXPO mode (the optimal SPD timings) and restart, it'll train again. Once trained you're looking at POST times of less than 30 seconds, which is still too much IMHO.  Stability-wise, we had no issues, but since AMD provided these kits, they've been extensively tested for compatibility. This isn't any criticism by the way; for both Intel and AMD, with the start of a new architecture, it's racing against the clock to get memory kits compatible at a firmware level. 

Note on BIOS POST

Actually, let me make a paragraph out of this information. The first time you'll start up your system it'll trains memory. Once you set your XMP/EXPO profile, it'll do that again. This process can take 2-3 minutes. Once your memory is trained POST and thus boot times will ramp up as fast as expected at say 15 to 20 seconds max. So don't worry about the rumors. 

Energy efficiency and heat

The Ryzen 9 7900X is a processor rated at 170 Watts; much like Intel's PL2 states, AMD now applies a PPT of 230W, so that means your processor can utilize that wattage. The specs aren't so shabby as the processor can utilize 1.475 Volts dynamically. All these factors produce all that heat we've been talking about. I want to add that much heat seems to originate from the memory controllers. The new IO chip also has fast PCI lanes and an IGP to deal with. With LCS you can keep this processor in the ~90 Degrees C domain under full load though; that's okay enough.

I like to add the following from the AMD reviewers guide:

It’s important to note TJMax is the max safe operating temperature – not the absolute max temperature. In the Ryzen 7000 Series, the processor is designed to run at TJMax 24/7 without risk of damage or deterioration. At 95 degrees it is not running hot, rather It will intentionally go to this temperature as much as possible under load because the power management system knows that this is the ideal way to squeeze the most performance out of the chip without damaging it.

Overclocking

As with all processors, you still have a bit of leech to overlock. With proper liquid cooling (an LCS kit with enough capacity), selecting all cores towards your maximum multiplier is the easiest way to overclock. With these temps at hand, we advise the voltage regulated by the motherboard (auto voltage). For Ryzen 9 7900X all-core max seems to be in the 5200~5250 MHz area with LCS, again that's all cores. 

Conclusion

The AMD Ryzen 9 7900X is a highly potent desktop processor, often outperforming the Intel Core i9-12900K in multi-core benchmarks while being priced lower.  If you're looking for a dedicated gaming processor, the Ryzen 9 7900X is overkill; the Ryzen 5 7600X/7700X or the Intel Core i5-12600K are better options. However, you need to keep a few things about the Ryzen 7000 series in mind. This is an entirely new platform. Therefore it has a different socket and chipsets and can only use DDR5 memory. Therefore, upgrading isn't quite as simple as installing a new processor and flashing the BIOS as it was in previous generations. While socket AM4 coolers will continue to function, a new motherboard and RAM are required for use with a Ryzen 7000 series processor. Further, the X670E-based high-end motherboards will cost more than the X570-based ones because of the X670E's dual IO chips. Memory with the DDR5 standard is now more expensive than memory with the DDR4 standard. On the performance side, AMD does well; however, we observe a scarce IPC improvement of just 3%, which may be combined with clock frequency reaching out to 5.6 ~ 5.7 GHz on some cores. That IPC made AMD pull open all available registers, the trade-in being thermal- and energy efficiency. In addition to the new AM5 platforms, PCIe Gen 5 is now within reach, but there is currently no purpose for it because no graphics card even requires PCIe Gen 5. We were also hoping that AMD would have seeded some samples of Gen5-ready NVMe SSDs; however, there are currently not seeded. Just so you know, we're not super certain that PCIe Gen 5 SSD will make a massive difference in real-world performance and user experience either; yeah, sustained speeds will reach +10GB/s, but you'll get the very same 4K read/write performance because the most significant thing going on is bandwidth. Seen from a generic point of view, a ZEN4 processor, simply put, makes everything faster. I'll be the devil's advocate here; if you're a gamer looking at energy efficiency, cool temps, and platform cost of ownership, the more interesting proc to get is the 5800X3D. It'll save you the cost of ownership for the total platform (mobo/ddr4), and you'll steer away from any possible heat issues. As a generic platform, however, the new motherboards are loaded with their latest features running from USB 3.2 2x2, 2.5 G LAN, and WIFI6E. That, combined with PCIe Gen 5.0, might make all the difference for you. If you do not plan to game on your new Ryzen 7000 PC, then you'll like that the Series 7000 now comes with a fully-fetched IGP; whatever you do, it'll get the job done (as long as it's not gaming).

In conclusion, we are impressed by the new level of performance that AMD brings to the table, Zen 4 is a step upward in performance, but the overall cost of ownership (of the platform) for consumers is steep. Probably good to know is that we had no stability issues or issues whatsoever, which is lovely for a new platform.It seems that ASUS is tempering the maximum power consumption of the processor from 235 to 175W, that does help with thermals and didn't cost much performance either. In the end this will be a difficult-to-sell processor given its unusual 12-core design, however for creators this might be a pure win, but likely these will go for the 7950X as the 150 USD extra on the total cost of ownership is worth it. In the end a lovely processor. However, it may be tactful to postpone your CPU purchase until Intel releases its Raptor Lake desktop processor family. Its performance should be good, and competition, in the end, will also drive prices down.


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