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Since a few weeks, a part of our Discord community has been playing with old GPUs in order to get the best performance in overclocking. This is what gave us the idea and especially the desire to dip our fingers into old GPUs that we had the chance to test and that left us an excellent impression. Of course, most of them have long since left the lab, but not all. We had to go through the “second hand” box and we have to admit that the second hand prices are still very high and do not really reflect the power of the GPU compared to the current offer.
So our first choice was a copy of the MSI R7870 Hawk that we had stored in the lab so that we could bring it out when the time was right, and here it is. Why this card? Simply because we still have all the tools and material to unlock the voltages for a final switch to LN2, which will be done first on our DOD, a phase change system that we will come back to in the rest of this article. This card can currently be found on second hand around 50 euros.
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The first time we had this model in our hands was in May 2012 and it was sold at that time for 349 euros. The “Hawk” series was very interesting because although it was below the “Lightning” series, we were entitled to an in-house PCB and integrated tools for overclocking such as three voltage measurement plugs for the GPU, the memory and the PLL.
In 2012, we had already been able to do a series of tests with the original cooling system and the gains were very interesting. MSI had also made available for this model and for overclockers, a LN2 BIOS that strongly debrided the card’s limits. So we flashed this R7870 Hawk but never ran it under cold conditions. Our first series of tests with the original cooling system allowed us to increase the GPU frequency from 1100 to 1300 MHz and the memory from 1200 to 1600 MHz. The current version of Afterburner allows us to have access to the voltages but I have in mind that the version 2.2.3 allowed to have a larger range. We are trying to find this version.
Now that we know that our card is perfectly operational, we head to Hwbot to note the best scores obtained with this card in the various benchmarks. The idea is of course to take the first place by starting with the 3DMark series.
[nextpage title=”MSI R7870 Hawk under cold:”]
Card preparation:
The first step will be to remove the cooling system in order to isolate the PCB from the cold. To do this, we will use charcoal gum on the front and back of the PCB. Our cooling system goes down to -50°C which will leave the GPU always at negative temperatures. The principle of insulation is to avoid having water in contact with the electronic components but here there is no risk. We also had to use a small adapter to put on the graphics chip to ensure a perfect contact with our DOD.
The difficulty in isolating this model lies in the presence on the back of the PCB of the MSI GPU Reactor, an additional mini-board attached to the back of the graphics card offering a voltage up to 5 times higher but with a cleaner signal which greatly improves the overclocking capabilities of the card. The MSI GPU Reactor is easy to install or remove.
But what is the DOD?
When I post pictures on our Discord, I get quite a few questions about my DOD also called phase change system. This one was made by Piotres and sent directly from Poland in May 2013 and as you can see, it is still perfectly operational.
We won’t go into the technical terms, but the basic principle is to provide cold at the end of the evaporator which will be in contact with either a processor or a GPU. The temperature at the evaporator goes down to -54°C at no load and during our tests with the R7870, the temperature goes up to -45.5°C, which leaves the chip at negative temperatures as GPU-Z indicates. You can see it here in operation on an Intel i9-9350K processor associated with an EVGA Z390 DARK motherboard.
Let’s use the GPU mount and attach it to our MSI R7870 Hawk in order to start the cold tests. The fan allows us to blow some fresh air on the power stage of our graphics card. For this first series of tests, we did not use any radiator on it.
What do the tests show?
The test configuration consists of an i9-13900KS overclocked to 5.8 GHz, a Teamgroup 7200 MT/s memory kit overclocked to 8000 MT/s CL34, all installed on a ROG Maximus Z790 APEX motherboard. The idea will be first to look for the maximum ” benchmarkable ” frequency under Time Spy by pushing the voltage to 1.35 volt which translates into 1.33 volt on the multimeter. In the next few days, we will try to find ways to exceed this voltage in order to try to go higher in frequency. The idea will then be to chain the benchmarks by crossing our fingers. We have opted for those that score in the 3DMark series.
Finally, the limit is around 1500/1525 MHz for the GPU and still 1600 MHz for the memory. Good news, the cold does not seem to disturb our Hynix memory chips. Despite a voltage of 1.33 volts, the graphics chip does not heat up too much and allows us to keep negative temperatures during all benchmarks.
And here are all the results obtained during this first session.
On these first six benchmarks, we were able to take the first place five times except for 3DMark Fire Strike Ultra where our graphic score is very bad without really knowing why. So it’s quite positive since this first session allowed us to score 127 points. We will do a second session very soon, maybe under LN2 if we manage to unlock the voltages above 1.35v and to deal with older benchmarks. Until then, come and share your experiences on our Discord and see you soon for the cold run of an old GPU!