Ryzen 7900 VS 7800X3D
Ryzen 7900 VS 7800X3D
It's quite pertinent considering how overclocking can counteract the main drawback of 3D Cache chips—lower clock speeds that restrict single-core performance. That's why choosing a setup with external clock support would be appealing for me when using the 7800X3D. I might even use DerBauer's lapper to fine-tune the IHS, since 3D V-Cache is very temperature-sensitive and contributes significantly to why boost clocks are so constrained on these chips. Researchers have already demonstrated that with proper adjustments and cooling, the 7800X3D can match the performance of a non-3D 7700X, which is a substantial improvement.
I wouldn't waste time on lapping, just try direct water cooling—either block or running water over the chips. I think you might get better results that way, but I'm too lazy to build that loop I've been putting off for over a year. I'll test myself later when I have more cash and stop being such a slacker. Probably start with an older AMD chip first, since mounting won't be so bad. Maybe check the FX 4100 specs on a used board—I don’t have a board right now, so I’ll need to buy one. Eventually I hope to get an AMD Ryzen 5000 or similar, aiming for something around $1000–1500 if I want a decent machine. By June 6th I’d like to be running it, but honestly I prefer portable desktops with batteries over a car. And don’t worry, I’m not really into prom stuff anymore.
I recently explored more details and it seems there’s a strong case for choosing the Ryzen 7900 instead of the 7800X3D. The main point is that the cache differences aren’t as significant as they seem. Comparing the 7700 with the 7800X3D, the 7700 provides only 8MB of L2 and 32MB of L3, whereas the 7800X3D offers the same 8MB of L2 and 96MB of L3. Still, the 7900 comes with a second CCD, giving it more cache space overall. It also runs better under stress, handles heat more effectively, and is now available for just $399—a solid deal for a 12-core processor. DeLidding is an option but comes with serious drawbacks. It’s easy to damage the capacitors near the IHS, it’s hard to cool the chip down without major hardware changes, and it eliminates the protective features of the 3D V-Cache. The taller die shape from 3D V-Cache also makes shaving the IHS a safer alternative. JaysTwoCents shared his experience with the 7950X, noting significant performance gains after adjusting his cooler to fit the lower IHS properly.
the performance of the 7800x3d comes from its cores accessing data quickly without needing to reach another cache, not just how much cache there is. The speed of the cache matters more than the total amount. I still think the 7900 is better because it’s free stock cooler and you can resell it for 10-20 dollars. More cores help too, and the x3d chips keep the heat away from the cores, improving cooling. Not everyone uses an air cooler or a custom loop, but if you want that extra boost, you could mount a die air cooler—but it would be complicated and heavy. For AIO or custom loops, it’s usually fine. I’m more of a straightforward approach; I don’t think lapping is worth the hassle unless you really need it. The IHS stays intact, so if warranty matters, just reattach it with silicone. If you prefer to thin the IHS, go as far as possible, or skip the retention height and use the cooler mounts instead. I’m curious about affordable direct die mounts for AM5—thermalright might have a budget option.
The 3D v-cache mod reduces the die size to maintain consistent Z height. The second CCD cache isn't a key factor here because the benefit comes from each CCD individually. This design helps especially in games with many dynamic objects or high player counts, like MMOs or multiplayer titles. Having double the L2 cache per core can further improve performance. Using just one CCD is sufficient since the advantage lies per CCD. An improper setup of the R9 7000x3D can limit its potential, but it's manageable if configured correctly. Choosing a 7900 over the 7000x3D CPUs is a good move. The real performance edge comes from games that are well-optimized and demand high frame rates, as these fully utilize features like 3D v-cache. Even on my 7950x3D, testing different configurations showed clear differences in frame consistency, especially for demanding scenarios. Generally, games that aren't memory-heavy but push system RAM limits benefit the most from upgrades like L3 caches. The L3 upgrade often makes a bigger impact than architectural changes, as seen when comparing the 5800x3D to the 7700x.
This situation is quite accurate and explains why I remain drawn to the 7800X3D while still weighing the options between the two CPUs. The positive aspect is that I won’t be making a purchase anytime soon. Of course, my current Ryzen 3700X is powerful enough for the new Radeon RX 7900-XTX Red Devil, but I tend to adjust settings rather than aim for maximum FPS. It’s not an all-or-nothing situation; it’s more about finding a balance.
The main concern is that my existing build isn’t fully optimized yet. I’m hoping for a price drop on the AM5 boards or a good deal on the 7800X3D. If I can snag one for the same price as the 7900, it would be a solid choice. I’m also curious about how the physical die was reduced to fit the 3D V-Cache—this adds an interesting technical detail.
Regarding cooling, I prefer air cooling over liquid systems, especially for mid-range CPUs. De-lidding isn’t an option for me. A well-designed case with quality fans can match the performance of a high-end AIO setup. My current build uses a Phanteks P500A with multiple 1800 RPM fans and upgraded components, allowing stable performance around 80°C.
If I upgrade to the 7800X3D, I’d aim for a solid daily OC of at least 5.2GHz All-Core. I’m hoping it will perform better than the 7700 while still being reliable. The trade-off is learning how the 3D cache is handled during overclocking. Overall, I’m focused on improving cooling and stability before committing to a new purchase.
Aircooling enthusiast 4.2g allcore on your 3700x at 1.4v? Typically I’d prefer lowering it for a lower vcore like 1.35v or 1.3v since you’re hitting diminishing returns, especially with a 7900xtx. Keep an eye on the video where Skatterbencher tests the 7800x3d—probably not feasible without direct die or water cooling, even if you push 115c which seems doable for such low voltages. Still, I doubt it’s worth it unless you’re comfortable with temps near 150°C. But as long as temp scaling on Zen4 holds, pushing past 115c might make sense. Running at 130°C isn’t ideal, though I might try it just for curiosity if the board doesn’t auto-shutdown. If you play games that don’t use a lot of cache, a 7700 with 5.4 allcore should be more satisfying, even with stock issues. Just consider lighter overclocking or check OC numbers from 7700 owners—Skatterbencher uses prime95 small ffts, which are mostly for testing stability, not real-world performance. I’ve heard AIDA64 can handle it, but sometimes you get occasional hiccups. For reliable low-end cooling at this level, the Giga B650 Aorus Master or ASUS X670 might be better options.
I run a 1.375V setup regularly for daily use. The 1.40V model is my absolute limit; I don’t push it every day. I’ve watched the ScatterBencher video and noticed something crucial isn’t mentioned – it’s not about direct-die cooling or carefully handling the IHS. He used stock IHS temperatures and just forced cooling with a large AIO and maximum fan speed. The thick IHS is a much bigger issue than most realize. AMD could have done better by making people upgrade to new coolers like any other socket, instead of sticking with AM4 compatibility. You’ll understand: a thick IHS on a high-density 5nm CPU acts like a heavy blanket, blocking airflow. JaysTwoCents even had trouble with his lapping on the 7950X and still saw over a 10°C drop. Also, the 7950X uses roughly twice the power of the 7800X3D, so it needs about double the cooling. With proper airflow and a good cooler like the Noctua D-15, you can comfortably air-cool the 7950X without hitting TJMax. The only CPU that really needs liquid cooling is the i9-13900K when you hit power targets above 300W – at that point, air cooling becomes essential rather than just an option.
I guess im just underestimating the impact of lapping the ihs over outright delidding it Though if you are gonna go to that length you may aswell thin it as much as possible and either customize the mounting (idk of those aftermarket am5 socket retention allow for lower ihs height) or use your cooler as mounting. Maybe thin it by 2mm or more The 3d cache ontop the 7800x3d is already a blanket on its own so thats why i reccomend outright delidding or water over die but lapping the shit out of the ihs and making at as thin as possible is an ok alternative For full cpu load i dont really expect it to run at 5.2 without bypassing the tjmax and allowing the cpu to run at 105-115c even with the lapped ihs unless you lap it way down, again the 3d cache itself is already a heat insulator and even on am4 where the ihs wasnt a retarded design the 5800x3d still runs hot. If you are fine with the cpu peaking at 115c for unrealistic stress loads and maybe staying more at 90 for some realistic stress loads then 5.2ghz is acheivable ig I personally dont suggest going to 115c unless its really the only option and volt is <1.2v cause theres usually always a better way (just adding more cooling onto the cpu) but here you are kinda forced to run it hot soo As for the lapping process if you are using a sanding belt that can heat the cpu up alot so beware of that. Ive never heard of anyone using a cnc or whatever that can machine metal to thin down the cpu ihs but that might be a viable method with how thick the am5 ihs is
I mean definitely De-Lidding offers the best solution. It’s possible I could opt for a full AIO setup but I lean toward air-cooling. Still, I agree a thorough lapping can significantly improve performance. For previous Intel CPUs, only minor changes were noticeable, but with the thick IHS of Ryzen 7000, the impact was substantial. In the video, Jay shaved just 0.8mm—product info suggests you could go up to 1.6mm before major fixes are needed. If he had done it right, maybe he could have saved another 6-7°C with a full IHS removal and a solid thermal paste like Thermal Grizzly’s Kryonaut Extreme. That would bring the temperature down by about 16°C compared to stock IHS, assuming good airflow. Most folks underestimate air-cooling, which is why you’re in that camp. A Noctua D-15 actually matches a 240mm AIO’s performance—tests confirm identical temps with proper airflow. Upgrading fans and coolers can push even a 280mm AIO to similar levels. It’s impressive how much air can help when used effectively. But you mentioned earlier that careful work could keep the 7800X3D under 100°C even overclocked on air cooling. That’s a solid point. If I take my time and do it right, I’m confident I can maintain temperatures below 100°C. I don’t know how far I’d push the overclock, but I’ll have some thermal margin if I get it done properly. The main concern is whether removing the die will damage it or not—this could be a strong reason to go with De-Lidding and an AIO.