AMD has just officially announced the AMD Ryzen 9 7945HX3D, the first laptop processor featuring the company’s excellent 3D V-Cache technology. And it’s potentially one of the most exciting mobile gaming chips AMD has ever released, as it uses a healthy dose of extra L3 cache to boost frame rates for the majority of games.
I say potentially only because it limits 3D V-Cache technology to its highest performing Zen 4 laptop chip, and then limits that solo chip to an exclusive deal with Asus alone. For one device, the Asus ROG Strix Scar 17 X3D.
“It will be available in a single laptop,” AMD’s Donny Woligroski tells us. “So this will be exclusively available, for the foreseeable future, in the Asus ROG Strix Scar 17.”
After being leaked earlier in the week, the machine will launch on August 22 this year, so a little summertime treat around Gamescom, then.
Ryzen 9 7945HX3D Specifications
Architecture: AMD Zen 4
Son : 32
Boost Clock: 5.4GHz
L2 cache: 16 MB
L3 cache: 128 MB
PDT: 55 – 75W
GPUs: AMD Radeon 610M
The chip is more or less identical to the Ryzen 9 7945HX laptop processor, but has the full 64MB of L3 cache tied on top of one of its eight-core chiplets. It has the same TDP and the same maximum clock speed of 5.4 GHz (although this is probably only achievable on the chiplet not sporting the additional L3 hat).
I’m a big fan of this processor, and in fact the original Asus ROG Strix Scar 17 machine it launched in. In fact, I’m a bit sad that it hasn’t been used in more laptops.
But why is it important to add extra cache to this already impressive chip, and why would you want it in your gaming CPU? The basic answer is that this is how every manufacturer extracts additional performance from their hardware in an age when it is becoming increasingly difficult to make silicon run faster.
The power and thermal costs of constantly increasing clock speeds make this a difficult path to follow, but adding a ton of extra cache to a processor or graphics card is a relatively easy way to get a bit higher performance without needing more power or cooling.
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Applications, especially games, need a lot of very low latency access to a huge amount of data. And the closer that data is to the actual processing silicon, the higher the performance. If the data is stored in a cache level that is actually attached to your chip, it can be used much faster.
If an application cannot find the data in the cache, when you have a small amount of memory attached, for example, then it must look further. And if it has to tap into your system memory, your PC’s RAM, then AMD suggests that it takes ten times longer than accessing data through cache.
This suggests that, compared to its non-3D V-Cache equivalent, the Ryzen 9 7945HX3D will deliver roughly 15% better gaming performance on average. And sometimes much higher.
Given the success of AMD’s 3D V-Cache when it comes to delivering the best gaming performance for its Ryzen CPUs, I’m still surprised that AMD has been so parsimonious in releasing more chips in the wild. . It first launched in the Ryzen 7 5800X3D in early 2022 and was the only 5000 series chip to sport the extra cache, until very recently when the Ryzen 5 5600X3D was released.
And the latter was only in very limited volumes exclusively at the Micro Center. So yes, AMD has a history of releasing very X3D chips and obstructive exclusivity deals for them as well. The Ryzen 7000 series only had three X3D chips itself, and again it was largely limited to the upper end of the range.
The fact that AMD is only using a single 16-core, 32-thread mobile chip as the home for its 3D V-Cache is a shame, but fingers crossed that this proprietary chip is just testing the water for d other mobile processors get the same treatment. . Because laptops are the perfect home for the extra performance boost that 3D V-Cache can provide; the higher frame rates of the extra L3 cache available are more noticeable at the lower TDPs and lower clock speeds of mobile processors.
We’re still in a situation where only one of the Ryzen 9 7945HX3D’s compute chiplets (CCDs) gets the L3 cache bump. Thus, the chipset drivers will have to work in real time, alongside Windows, to determine which workloads go to which chiplet. Do they prefer higher clock speeds? And you go to the one without the 3D V-Cache. Do they like a little more hiding? You know where to go…
This complexity can add some issues, but the Ryzen 9 7950X3D desktop did pretty well on this score, to be fair. While games tend to benefit the most from higher cache levels, a more affordable eight-core laptop chip with a CCD and the extra 3D V-Cache is what I’m sticking with.