Intel Alder Lake ES leaked: 4.6 GHz clock, high power draw

Intel Core-1800: Alder Lake ES with quite high clock speed

Interesting info has shown up about the upcoming Intel Alder Lake CPUs, the first big.LITTLE desktop CPUs. Igor’sLAB has covered a sample called Core-1800 with 16 cores and 24 threads. The ES already shows promising clock speed and boost values for different active core counts. Also notable is the power draw. Intel doesn’t seem to be about to return to more power-efficient CPUs despite the 10nm process, PL2 is still over 200 W.

A new generation of Intel desktop processors (11th generation Core aka Rocket Lake) has just recently been released, but a bigger change is being prepared: Alder Lake processors finally with a 10nm manufacturing process, a new architecture with high IPC as well as a new LGA 1700 platform and DDR5 memory. This is supposed to come on the market at the end of this year and samples have been in place for some time, so we are slowly going to learn more details.

Igor Wallosek from igor’sLAB (and previously from Tom’s Hardware) received the specifications of an engineering sample of Alder Lake-S (i.e. desktop version of the CPU) with B0 stepping. This should no longer be an early sample, so it suggests a lot about the specs, but at the same time it is still not a final configuration. In other words: although the clock speed is already promisingly high, it may end up even higher in shipping products at the end of the year.

The ES is marked Core-1800, which differs from the previous practice of ES processors being “nameless”. But it’s probably not the name that the processor will actually bear after the commercial launch. Core-1800 is a sample with a full number of cores – eight big “Golden Cove” cores (which provide 16 threads thanks to HT) and eight little “Gracemont” cores (which provide only 8 threads, so the whole has 24 threads).

10nm won’t end the era of high TDP in PL2/boost

The Core-1800 has a 125W TDP, so Intel is not planning to push it lower even when the desktop CPUs finally switch to 10nm process. And it also seems to retain a relatively power-thirsty turbo boost. According to Wallosek, the sample has its PL2 (i.e. the maximum power draw during boost) set to 228 W. This is an improvement over up to 251 W with 14nm Rocket Lake CPUs, but only a small one. Unfortunately, the end of the 14nm era does not seem to mean an end to the high power draws that Intel has been allowing for their desktop processors.

For comparison: AMD desktop processors have a maximum power draw of 142 W. This Boost with power consumption up to PL2 level will likely again be limited to a certain period of time according to Intel’s specifications, but those are probably going to be largerly ignored by motherboards again. A high PL2 could indicate that Alder Lake is still not ready to compete with Ryzen in multi-threaded performance at identical power draw and the performance will have be reached at the cost of increased power consumption.

But what is the most interesting bit in this leak: clock speed. As already mentioned, the chip is still just an ES, not a production processor, so the clock speed is probably lower than what you will see at the end of the year. The base clock is reportedly just 1.8 GHz, which likely means the big cores (although this value is something I would personally expect from the small cores).

Alder Lake-S ES processor data (Source: igor’sLAB)

Boost clock speed

However, the boost already shows a picture much more optimistic. The maximum turbo boost is reportedly set at 4.6 GHz, which raises hopes that the final pieces will be able to reach up to 5 GHz again. Alder Lake could have up to 20–25% higher performance per 1 MHz than Rocket Lake and Tiger Lake, so the performance per thread would go up significantly. The Core-1800 processor only allows this boost for a maximum of two cores.

The cluster of eight big cores permits 4.0 GHz as the maximum clock when all cores are loaded (i.e. maximum all-core boost). The intermediate values are 4.4 GHz for 3–4 active cores and 4.2 GHz for 5–6 active cores. As you can see, the ES still seems to be using boost control with fixed limits for specific numbers of active cores, and not a more flexible free clock control like as employed by Ryzen (except for the 1000 generation). Intel has started supporting something similar with Adaptive Boost Technology, but that is currently reserved only for K-models of Core i9, other processors do not have it. In theory Intel could possibly enable this boost mode in all the Alder Lake generation processors, but this ES or the platform used do not seem to do this yet.

Gracemont will reach at least 3.4 GHz

The little cores will have their own separate rules for boost and clock rate. We don’t know their base clock (unless it’s also 1.8 GHz, I can think of an explanation that the value for the whole CPU is officially specified so low precisely because the little cores force it). But of course, even these cores have a boost. Its clock will reach up to 3.0 GHz for the state when all (or 5–8 little cores) are loaded. If only one to four little cores are loaded, their clock speed can rise up to 3.4 GHz. Again, these may not be the final values, there may be improvements.

Intel Alder Lake-S CPU sample for LGA 1700 (Source: VideoCardz)

Igor Wallosek also states that in the screenshot from HWiNFO64, which he received, the processor ran at a speed of 4.2 GHz (big cores) with a voltage of 1.3147 V. It is not clear whether this is with the automatic boost mode or perhaps with manual overclocking. Also, the final processor may again differ in voltage from this ES, so don’t take this as the final truth.

So this information reveals to us how Alder Lake will behave in terms of boost – much as expected, the clock speed of little cores will be lower than of the big ones. The question is whether the clock speeds won’t actually scale down to a similar value for both small and big cores anyway, once you load the entire 16-core CPU while constraining the power consumption to the 125W TDP/PL1. The high maximum boost gives hope that Alder Lake has not sacrificed clock potential in order to get the high IPC that its Golden Cove core is expected to achieve. If a regression occurred in the clock speed, it would in the end reduce the performance achieved. Whereas, if the clock could be kept as high as with Rocket Lake, the performance per thread would increase by the entire value of the jump achieved in the IPC.

Read more: LGA 1700 socket won’t be compatible with current coolers

PCI Express 5.0, DDR5

Recently information about the Alder Lake platform has also been leaked, according to which not only the processor but also the chipset will be an interesting update. The 600-series chipsets will be connected to the processor (at least for the more expensive ones) via DMI 4.0 ×8 . This is the equivalent of PCIe 4.0 ×8, four times the bandwidth of most desktop platforms today (except X570 and Z590 where the new platform will be just 2× as fast) and the same as that provided by the AMD TRX40/TRX80.

Diagram of the Intel Alder Lake-S desktop platform with a 600-series chipset (Source: VideoCardz)

Not only PCIe 3.0 lanes, but also PCI Express 4.0 (perhaps up to 16 lanes) will be provided by the chipset this time, so the platform would really have a lot of fast connectivity. In addition, PCIe 4.0 ×4 for directly connected SSDs and PCIe 5.0 ×16 for GPUs will be provided by the processor.

DDR5 memory will also use Gear 1/Gear 2 (divider) on LGA 1700

The processor will support DDR5-4800 and DDR4-3200 memory (depending on which board you buy, those with DDR4-3200 will typically be cheaper and intended for users upgrad from older hardware, already having memory from previous PC).

The memory clock divider, or Gear mode, which has already appeared with Rocket Lake processors, will probably be used for high frequencies, especially with DDR5. The release notes for the new HWiNFO v7.03-4460 Beta mention a fix to Gear Mode detection on Alder Lake processors, which means that this feature seems to exist on the new platform and processors.

Release notes for HWiNFO v7 03-4460 Beta state that Alder Lake will have a memory controller with Gear 1/2 modes (Source: HWiNFO)

This means that in order to achieve high DDR4/5 frequency, the memory controller switches to half frequency relative to the DDR frequency, otherwise it would not be able to maintain stability handling high DDR4/5 frequency. RAM tuning enthusiasts have not welcomed this, as the Rocket Lake memory controller is not able to achieve as high frequency in 1:1 mode as Comet Lake was able to before. But the use of this new controller with a clock divider is probably forced by the preparation for DDR5 memory with its high frequencies.

Sources: igor’sLAB, HXL

Translated, original text by:
Jan Olšan, editor for Cnews.cz


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