It’s only been about two months since MainNet launch on Chia and I feel like there is still much to be discovered with the plotting process. I recently decided to upgrade the RAM on my plotting machine from 32GB (4 DIMMS) to 64GB (2 DIMMS). I’ve learned in the past that when using Big DIMMS (32GB per stick in this case) that you need to pick RAM that is in the Qualified Vendor List (QVL) for the motherboard. In order to not get caught again with low RAM like before, I wanted to leave two slots available this time. This will leave an upgrade path to 128GB if that is needed in the future. This is why I choose two 32GB sticks. The kit that I went with was the Thermaltake TOUGHRAM RGB 64GB (2x32GB) DDR4 3600MHz C18 (amazon affiliate link). This was the only one I could find for my motherboard.
I got the kit and installed into the plotting machine. I did a single plot with the same settings I’ve done before (6 threads, 3416 RAM, Solo NVMe). To my surprise, my times improved as shown below:
|Plot Times||32GB |
There is roughly a 700s speed up. So what could be happening here? There are a couple things that can cause this:
- AMD processors are known to perform better with faster RAM. Ryzen processors use Infinity Fabric which is tied to the RAM speed. Faster RAM results in faster Infinity Fabric speed.
- This could also be an effect of going from 4 DIMMs to 2 DIMMs. It has been known that 2 DIMMs can overclock better than 4 DIMMs. Although I’m not over clocking here, just using XMP.
But there are more questions that needs more testing:
- The RAM timings are worse with the 3600 Kit. Does this mean that RAM timings don’t matter that much? Is RAM MHz the king?
- Will this improve parallel plotting times?
It takes a while to test these things so I will try and answer these questions. The reason for releasing this blog early was so that people know that if you are going to build an AMD plotting machine to get the fastest RAM that you can get. Right now, its really hard to hit 4000Mhz with RAM and have the Infinity Fabric match it at 2000Mhz, it seems like 3800 RAM is the sweet spot? AMD has said that it should be possible to do this, so they’re working on the AGESA fixes to get it there. You will have to do your own research on your specific motherboard and processor combo.
Another bit of information is that I’m currently testing a machine that has an AMD 5700G. I will release that information once I have it.
Keep on Farming on!