Under cold
We start this session with a quick survey of what’s left in dry ice, around 10 Kg out of the 20 Kg left after the previous day’s session on Raptor Lake. Here’s a photo of the 20 Kg parcel, well underway with less than 4 Kg in the middle of the Y-cruncher session.
So we’ll start the Session on Y-cruncher, which is, along with 7-zip, one of the two benchmarks to be done for this competition under Arrow Lake. Why Arrow Lake? Because the core limit is set at 6, and without hyper-threading, Arrow Lake outperforms Raptor Lake on multicore benchmarks.
The first step is to switch Ycruncher to 6Ghz on the CPU with RAM in ambient. This may seem straightforward at -70°C, but not in the case of a very bad Ultra 7 265K on the core. Impossible to set 1.42V or more, under penalty of severe downclock, and impossible to benchmark at less than 1.425V during initial tests. This lasted well over an hour, enough time to test BIOS parameters and make a few adjustments under Intel XTU. In the end, the bucket was a little cold. Adding acetone dropped it from -55 to -64°C (yes, that’s not much, but strangely enough, on ARL the bucket is warmer, around -71 on RPL). With a voltage of 1.415V and a lower temperature, we manage to get through Y-cruncher without any problem and without any loss of performance, but it’s still borderline and it will be difficult to get much out of this CPU on other sessions.
The memory can now be cooled down, so we don’t think too much about it, taking it down to -70°C in a matter of seconds thanks to the highly responsive aluminum LN2 pot.
First benchmark: Y-cruncher 2.5B at 6GHz
We start with the Benchmark that will have taken us the longest, the most severe for IMC and CPU. If a profile passes here, it goes on 7-zip. We start with ambient memory, 8800c36, then push it to 9000, 9200 and finally 9400C36. With memory at -70°C on a motherboard that’s not up to the level of the Apex, OCF and Tachyon, this is quite a feat all the same. The only downside is the train time: I clocked up to 3 min 15s to train the profile to 9400C36.
Once the RAM is pushed to its maximum, we push a little more D2D, rather limited to 34-35 because of the cold and a VNNAON locked at 0.82V. The NGU is up to 38 and the cache to 51. With such high frequencies, the system is on the verge of stability, but a respectable score of 73.656s is obtained in the end.
Second benchmark: Z-zip at 6GHz
After perhaps 9 hours in the cold on Y-cruncher, pushing to the max and learning the platform (IMC, SA, memory voltage, CPU timings and limits), we now move on to 7zip. A few tests were carried out beforehand to see if performance was acceptable, but it’s time to push a little and validate a score.
On 7-zip, we were able to push the memory frequency to 9400C36, D2D to 34, NGU to 38 and cache to 51. I was also able to run the benchmark at 9494C36 by pushing the SOC’s BCLK to 101 MHz. With this memory profile, the final result is 82135 pts on 7-zip, some OS and Bios tweaks are involved, but we won’t reveal the magic recipe.
Latest benchmark: Max Freq in DDR5, target 11000 Mt/s
Just before this session, I made a post on X, teasing the session and giving me a goal of 11000 Mt/s in memory frequency, let’s see if the goal is reached.
I’m born for this moment😍😍😍 Can’t wait https://t.co/CXjdAmy0Qo
— Maxsun Official (@MaxsunOfficial) March 17, 2025
So we start with less than 1 kg of dry ice left, if not less. Fortunately, the CPU is down onto 2 cores, and frequencies and voltages have been reduced, so there’s no risk of overheating. We start with a profile that had worked in ambient with 5350 MHz in CL48. Here, it’s impossible to go beyond CL48, so we’ll make do, with ram voltage at 1.45V, SA and IMC at 1.5V.
We therefore manage to train 10800 Mt/s (5400 MHz) in CL48, then on Intel XTU, we increase the BCLK of the SOC to 104 MHz, reaching a frequency of 11200 Mt/s (5600Mhz ), which is the target.
At the end, with the last remaining grams of ice, I manage to reach 11067 Mt/s, but it’s impossible to run Windows. Temperatures rise again, and it’s almost 4 a.m., time to call it a day.
