AMD calls its Zen 4's 15% Single-Threaded Uplift "Conservative" and their 5.5GHz clock speeds "very easy"
Is AMD sandbagging us?
Published: 27th May 2022 | Source: TechPowerUp |
Should we expect Zen 4 to be better than claimed?
When AMD showcased their Ryzen 7000 series processors at Computex, a lot of hardcore PC enthusiasts were unimpressed. AMD's claims of a "^15% single-threaded uplift" seemingly implied that the majority of Zen 4's performance gains would come from clock speed enhancements and not IPC gains, leaving many Ryzen fans concerned that AMD could struggle against Intel's next-generation CPU offerings.
In a recent interview with TechPowerUp, AMD's Robert Hallock stated that AMD was being "deliberately conservative" with their single-threaded performance numbers at Computex. Beyond that, Hallock confirmed that AMD would be discussing the "exact breakdown of IPC vs frequency contribution" of Zen 4's performance gains this summer.
At Computex, you showed a 15% single-thread performance gain over the Ryzen 9 5950X. Wouldn't that only put the gaming performance on par with 5800X3D?
I think it's too early to say actually. We were deliberately conservative with our number on single-thread performance. We do intend to publish the exact breakdown of IPC vs. frequency contribution later in the summer, also including performance, power, and area on the new process. As far as what stacks up against what, I think it's too early to say, we're still in silicon bring-up.
Are AMD Sandbagging?
AMD's 15+% single-threaded performance figure comes from a single benchmark, Cinebench R23. To put things simply, a single benchmark figure is not enough to fully describe the performance gains that are offered by a new CPU architecture. When AMD discusses IPC gains, these gains usually come from an average performance gain that was tested using a variety of applications. IPC gains are usually very application specific, and often vary greatly on an application by application basis.
What's also worth noting is that AMD's numbers state that PC users should expect a greater than 15% increase in single-threaded performance. This means that Ryzen 7000 users should expect more than 15% of additional single-threaded performance from AMD's new architecture. If 15% could be seen as a minimum level of single-threaded performance improvement for AMD's Ryzen 7000 series processors, that would be a big deal for AMD.
To make a long story short, we need to see a lot more data before we start making any major performance claims regarding AMD's Ryzen 7000 series processors and AMD's Zen 4 CPU architecture.
When discussing CPU overclocking, AMD's Robert Hallock stated that "5.5GHz was very easy for us", and commented elsewhere that their 5.5GHz clock speed demo was using a early Ryzen 7000 series CPU without applying an overclock or using an overly exotic cooling setup. This CPU was cooled using a 280mm AIO liquid cooler, not a water chiller.
One of the largest areas of improvement for AMD's 5nm Zen 4 CPU architecture is in its core clock speeds. With Zen 4, AMD's Ryzen processors can run at higher clock speeds than ever before. This change will deliver performance gains for AMD across all workloads, as clock speed gains should enable performance improvements across all workloads. When other architectural improvements are considered, even larger performance gains should be possible, assuming that AMD architectural improvements with Zen 4 apply across a broad range of applications.
What can we expect from the processors in terms of CPU overclocking?
I'm not gonna make a commitment yet on frequency, but what I will say is that 5.5 GHz was very easy for us. The Ghostwire demo was one of many games that achieved that frequency on an early-silicon prototype 16-core part with an off-the-shelf liquid cooler. We're very excited about the frequency capabilities of Zen 4 on 5 nanometer; it's looking really good, more to come.
If AMD's 5.5GHz clock speeds were "easy" to achieve, it is possible that AMD's flagship level Ryzen 7000 series CPUs may be able to deliver even higher boost clock speeds. Perhaps AMD's Ryzen 7000 series CPUs will be able to reach 5.7GHz, surpassing AMD's early silicon. Or maybe Ryzen 7000 series users will be able to achieve higher clock speeds though CPU overclocking.
Should we expect more from Zen 4?
Assuming that AMD is not lying to us when they say that their Zen 4 performance claims from Computex were "conservative", then we should assume that AMD has some more impressive performance gains to show us later this year. That said, it remains to be seen how well Zen 4 will perform in critical workloads like gaming and content creation, or how the addition of AVX-512 instructions will improve AMD's performance in today's workloads. AMD still has a lot to show us with Zen 4.