My recent experience with the new AMD 7000 series processors and related motherboards

[Nenon]

8 hours ago, lmitche said:

OK, so the Hdplex 500W GaN AIO(All-In-One) ATX Power Supply break-in period is complete. After several long listening tests, as a starting point power supply for a new build, this solution is the best that I have found.

 

@lmitche did you have a chance to try a good quality ULPS (and well burned-in, as these things really need at least 4-5 months) with the Taiko DC to DC ATX? I guess not given the comment above. 

This is my golden standard for powering up an audio computer these days. I haven't seen anything coming even remotely close. 

 

Good to hear you like those AMDs. 

[Nenon]

On 8/24/2023 at 9:16 AM, lmitche said:

@nenon To be clear, my experiment here was to find the best relatively inexpensive (<$200) power supply for someone starting from scratch. For some people, budgets mean that the cost of investing in a new music server will take some compromise. Rather than compromise on the server sound quality (SQ), many people prefer an inexpensive power supply to start. The goal is to purchase a music server that will later scale up in SQ once the funds for a better power supply are available.

Yes, that makes perfect sense, and it's a good way to start indeed.

 

On 8/24/2023 at 9:16 AM, lmitche said:

AMD Ryzen 7000 builds will boot with an 800 watt Hdplex DC-ATX/ULPS and beats the SQ of the Intel servers with the Taiko/ULPS.

This is interesting. So the Ryzen 7700 boots with the ULPS+HDPlex800 ATX but it does not boot with the same ULPS+Taiko ATX? One could easily make an assumption that the Taiko ATX is not able to handle the load, but I think it's the other way around.

 

If a computer can't boot with a specific power supply, this is 99.99% of the time related to the 12V EPS rail. 

- The Taiko 12V rail is spec-ed at 45A (540W) and can handle 80A peaks (960W).

- The HDPlex800 12V rail is spec-ed at 60A (720W) and can handle 90A peaks (1080W).

- Technically, the bottleneck on both is the Molex connector pins. Those are spec-ed at 5A. With 8 positive pins across the 2 x 8-pin EPS connectors, we are actually limited to 40A (480W). 

In the context of a 95W TDP CPU, none of the above limits are relevant. A 95W TDP CPU can peak at 200-300-400W for a short period of time at boot, but with nearly 1000W peak capabilities on both of these ATX, that can't be a problem. 

 

So what else might be going on? The HDPlex accepts 12V-63V DC input. The Taiko accepts 16V-48V DC / optimal 19V-35V DC (much narrower range). Also, the Taiko has a very aggressive and sensitive protection. I managed to kill the first prototype within hours, so Taiko dialed-in the protection to be quite aggressive, so it can protect the sensitive GaNfets. The downside of this is that as soon you drop under 16V even for a fraction of a second it turns off automatically. That's not easy to catch with a standard voltmeter/multimeter. My guess is this is what is happening in your case. You need to use a quite size-able transformer and inductors in the ULPS, so the voltage does not drop too much at peaks. Maxing out the voltage output also helps. 

With the Taiko, you might be down to just around 16V for a fraction of a second, and the power supply will turn off. With the HDPlex you can go down all the way to 12V (which I doubt it happens).

 

The bottom line is that a well designed and sized ULPS should work fine with the the AMD Ryzen 7000 CPUs (with the Taiko ATX that is).

Just to be clear - I don't build custom ULPS, so that's not the reason I promote this solution. I have zero financial benefit here. I've published everything I know for DIY, so people can enjoy a state of the art power supply. 

There are people in the "Building an Unregulated Linear Power Supply" thread who might be willing to help if you are interested to explore a cost no object solution or perhaps someone may offer a well burned-in LPS. 

 

Drop a line there if you are interested. 

Hope that helps. And I totally get your point about the affordable start with options to upgrade down the road. HDPlex will be my go to for that as well.