Overclocking: Air Vs. LN2
Before wrapping up, we wanted to see if there was a strong correlation between a processor's maximum frequency with liquid nitrogen cooling and what it is capable of with air cooling. This has significant appeal: why bother spending precious time and an enormous quantity of LN2? It could be sufficient to pre-select the best processors based on their performance under air cooling, and then test only the best contenders using liquid nitrogen cooling.
So we revisited our 10 Ryzen CPUs and found the maximum frequency of each at 1.35V. The table below allows us to make a comparison between the room temperature results and those with liquid nitrogen.
| Sample | Date of Fabrication | Max Freq. @ 1.35V (MHz) | Max Freq. @ -196°C (MHz) | Ideal Voltage @-196°C (V) |
|---|---|---|---|---|
| Ryzen 7 1800X #1 | 1703PGT | 4050 | 5320 | 1.85 |
| Ryzen 7 1800X #2 | 1711SUT | 4025 | 5220 | 1.85 |
| Ryzen 7 1700X | 1711PGS | 3975 | 5170 | 1.85 |
| Ryzen 7 1700 #1 | 1713PGT | 3900 | 5050 | 1.85 |
| Ryzen 7 1700 #2 | 1709PGT | 3900 | 5120 | 1.85 |
| Ryzen 7 1700 #3 | 1713PGT | 3925 | 5150 | 1.94 |
| Ryzen 5 1600X | 1711SUT | 3975 | 5250 | 1.85 |
| Ryzen 5 1600 | 1713SUT | 3900 | 5075 | 1.92 |
| Ryzen 5 1500X | 1712SUT | 3850 | 5030 | 1.85 |
| Ryzen 5 1400 | 1714SUT | 3900 | 5000 | 1.8 |
- At the top of the table, the 1800X CPUs dominate with air, just as they did in our LN2 tests. It seems like a processor capable of passing Cinebench R15 at 4 GHz with air cooling could be able to do 5.2+ GHz under the influence of LN2. The difference between our first and second samples is nevertheless more pronounced with liquid nitrogen than cooling at room temperatures.
- The 1700X tends to reinforce our observation; it finishes just below the 4 GHz mark with air, and just below 5.2 GHz with LN2.
- The same observation applies to our 1700s. The best with air cooling is also the best with LN2, but an important variable also comes into play: ease of use. Our notes show that these processors gave us a hard time. The samples that struggled under LN2 cooling were problematic under air, too.
- Looking back at the Ryzen 5 CPUs, we could say that a processor able to hold 3.9 GHz at ambient should be capable of benching at around 5.1 GHz. Obviously, these numbers aren't always exact, but they do illustrate a trend. This pattern seems to prove correct with the exception of Ryzen 5 1400, which should have been able to reach a higher frequency with LN2. It may have, too, had it not stopped progressing before 1.8V.
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