Intel’s PAO (Process-Architecture-Optimization) process hasn’t been as easy to follow as the old tick-tock system. Where tick-tock produced a steady cadence of die shrinks and new architectures, PAO is a bit more flexible. Intel’s new Goldmont Plus architecture is the basis for its recent Gemini Lake platform launch. Gemini Lake devices are now marketed under the “Pentium Silver” brand, and Intel is finally sharing a bit more information on how the new chips improve on Apollo Lake and its significant uplift compared to Silvermont.
The new chip is supposed to improve performance by up to 15% compared to previous Apollo Lake processors. Intel has now released optimization guides for the new chip and they detail what changes have been made from Apollo Lake (Goldmont) to Gemini Lake (Goldmont Plus).
The new cores have a wider back-end pipeline and can retire up to four instructions per cycle, up from three. Fetch and decode are still limited to three instructions per cycle, however. Branch prediction performance has been improved, and there’s a much larger 64KB shared L2 pre-decode cache (64KB, up from 16KB). There’s also now a dedicated port for the JEU (Jump Execution Unit) that didn’t previously exist. AES instruction latency and throughput have both improved, with larger load/store buffers, improved store-to-load forwarding latency, and an increased L2 cache (from 512KB per core to 1MB per core). The SoC CPU cluster is now organized into quads instead of pairs with more L2 allocated on a per-core basis. Goldmont-derived SoCs used 2-4 cores, typically with 2MB of L2 cache total. The new Goldmont Plus SoCs have four cores and 4MB of L2 cache per core cluster. If Intel follows its previous trend and releases a dual-core variant, it’ll probably use a 4MB L2 cluster as well.
The performance uplift from these new processors isn’t likely to be huge, and the performance gap between Intel’s entry-level and ultra-low-power “big core” chips is going to remain significant. At the same time, however, we’ve seen noted evolution since Bay Trail debuted back in 2012. Goldmont was a huge jump over the Silvermont architecture and if Goldmont Plus delivers as well, it should make low-cost, entry-level ultralight systems that much more attractive.
Goldmont Plus is a quick way for Intel to boost performance of its own entry level hardware, though it’s still not clear how much we’ll see ARM and Intel slugging it out in this segment. Microsoft is putting a push behind devices with Snapdragon 835 processors and x86 emulation, but we don’t know if Intel and ARM hardware will compete in the same TDP brackets or not.
Published at Thu, 28 Dec 2017 19:21:14 +0000