Coffee Lake processors

Core 9th Gen Coffee Lake series processors

Back in 2018 Intel announced that it would release Coffee Lake S-series processors. Coffee Lake started as 8th gen six-core processors and now this was expanding to eight-core processors. These are all based on the LGA1151 socket and will require a Z370 or Z390 motherboard chipsets. Depending on SKU version they have a TDP at 95W, with now 127 Watts for the 9900 KS. There are a total of four 8-core models.

While not mandatory, the Z390 chipset based motherboards are recommended for the 8-core parts. These have an improved VRM design. The Coffee Lake 9000 is also based on a 14nm fabrication node, with desktop models in 6-core and 8-core variants. The initial three launched are all K models (which are unlocked) in this Coffee Lake-S (9th generation series).

Architecture

The Coffee Lake series processors are a refresh of the existing architecture and, as such, the core basis is the same (as well as IPC). If we look back a little further, Coffee Lake-S shares design elements found in the Kaby Lake and Skylake architecture but got scaled upwards to 6 and 8 cores. Intel processor caches then; for Coffee Lake the L2 cache is 256 kB per core. The L3 cache is dependent on cores, but also whether or not the proc has SMT (Hyper-threading) enabled. 

• 9900K(S) - 8c/16t has 16MB L3
• 9700K - 8c/8t has 12MB L3
• 9600K - 6c/6t has 9MB L3

So yes, Intel has been tweaking L3 caches based on SMT and the number of cores for Coffee Lake-S.

The Processor and PCI-Express

• Coffee Lake Quad, Six and Eight core procs get 16 PCI-Express Lanes 3.0
• Kaby Lake-X Quad core procs get 16 PCI-Express Lanes 3.0
• Skylake-X six and eight core procs get 28 PCI-Express Lanes 3.0
• Skylake-X ten core procs gets 44 PCI-Express Lanes 3.0

The Coffee Lake procs support dual-channel DDR4 and 16 PCIe 3.0 lanes. The new platform also offers support for Intel Optane. The chipset will add additional PCIe lanes for your storage connectivity. In-between the processor and the chipset is an updated DMI (revision 3.0) link (equivalent to a full PCIe 3.0 x4 link). Now, you will probably have noticed that many motherboards will offer two or three M.2 storage units. So how would that work out with an x16 gen 3.0 processor you wonder? Well, the Z390 chipset offers 24 PCIe lanes. Extra 3rd party SATA / USB controllers and thus M.2 storage units can draw their bandwidth from here. 

How does it Turbo?

So, I've mentioned it already. When, say, a 9900K is listed as having a 5 GHz Turbo, that typically doesn't mean it's on all cores. One or two of them could do that, but using more cores would drop the frequency on the number of active cores. For the 900 KS this thus is activated on all cores. Normally if the motherboard follows reference specifications, your clock frequency will drop after, say, 30 to 60 seconds of full load. Here is an overview of the processors and their clock bins:

And that is how Intel manages that. Again, as an example: the 9900KS will boost to 5000 MHz on all cores. The duration of that all-core 5 GHz is dependant on other factors as well, the motherboard configuration, some run them 30 seconds, others 128 Seconds and then drop down to 4.7/4.8 or something. So the effect here is relative. You can configure this in any motherboard BIOs though, it would not be an issue to run a 5 GHz turbo on all cores all the time, at the cost of a notch power consumption.