New AMD Zen 4 launch

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whispercat
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New AMD Zen 4 launch

Post by whispercat » Mon Sep 26, 2022 1:35 pm

I have a couple of questions about thermals and performance comparing Zen 3 and 4.

In Zen 3, the 8-core 5800x ran hotter than the other Ryzen 7's and even Ryzen 9's. This was apparently because of the CCD, for technical reasons I don't quite understand. So, at the time, when I was contemplating getting a Zen 3 system, I was looking at a 5900x rather than the 5800x to avoid the hotter CPU.

Now with Zen 4, all the 7000 series CPUs reportedly run hot.

My first question is: For the 8-core Zen 4 (7700x) will this follow the same CCD issue as the previous Zen 3, 8-core chip and run even hotter than the other 7000 series?

Second: I am trying to decide between a 5900x, a 7600x and a 7700x. For my use, I probably don't need more than 8 cores. But I really want to keep thermals down. I'm also wanting my next build to last a long time, so future proofing is also on my mind. I'm not sure if 6 cores would be enough in the future. I don't game at all, but I want to get more into video editing. My needs are modest right now (90% office work, 10% video editing, 1% 3-D modelling), but that could change in say 5 or 6 years.

I'm really confused about whether to get a Zen 3 or 4 system.

whispercat
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Re: New AMD Zen 4 launch

Post by whispercat » Mon Sep 26, 2022 6:32 pm

After doing some research, I found out that in Zen 3 there were two CCDs on the higher end 5900x and 5950x CPUs, and now also in Zen 4 with the 7900x and the 7950x. When the heat load is spread out over two CCDs, apparently temps don't get quite as hot. When there is only one CCD, temps are higher, as in the case of the 5800x and 7700x (one CCD with 8 cores).

So it looks like the 7700x will carry on the same design as the 5800x (with only one CCD) and run hotter than the other 7900x and 7950x.

However, I also found out that in Zen 4 you can turn on an eco mode feature (requires rebooting) which drastically reduces temps, yet does not impact performance too much. If I got the 7700x (the sweet spot for me since I can't justify the extra jump in price for the 7900x) the eco mode feature would be useful for everyday productivity, whereas when I want to do something more intensive like video editing or 3-D modelling, I suppose I could always turn eco mode off to get full power.

I just hope I can still air cool the 7700x.

nomoon
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Re: New AMD Zen 4 launch

Post by nomoon » Tue Sep 27, 2022 2:56 pm

What is a CCD in this context? I tried a quick internet search and haven't found a definition yet. It's the photo detector type.

Japanese Capacitor
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Re: New AMD Zen 4 launch

Post by Japanese Capacitor » Wed Sep 28, 2022 10:17 am

There are plenty of materials explaining CCDs, but instead of worrying about that I would wait for Raptor Lakes - then we will see what is better choice for you. If they will be competetive (I'm not into leaks and gossip stuff, but from what I know they will be comparable), it's worth to wait a little longer for non-K ones: for last few years they were noticeably less power hungry (but you can power limit any ofc and it somethimes even make sense with flagship ones); noticeably cheaper and unnoticeably slower (at worse literally few %). Paying for K/X is paying for Intel vs AMD benchmark fights costing unreasonable power consumption and laughable overclocking potential leading it even further. And such shit costs even more?!

And generally Ryzen cpus, especially higher-end ones, used to be just harder to cool due to their construction, but also default behaviour (boosting; voltages; PBO). Intel used to be easier and predictable here - it's just about power draw which also differs with various usages (you won't see infamous 12900K's 241W during e.g. gaming)

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Re: New AMD Zen 4 launch

Post by CA_Steve » Mon Oct 03, 2022 6:01 am

Die shrinks (more wattage/heat in a smaller area) and the desire to run faster/further up the voltage/freq curve makes the X chips run so hot. As you noted, you could:
- enable the eco mode
- wait for the non-X parts to come out..I expect they be 65W TDP parts.
- limit the TDP in BIOS.

whispercat
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Re: New AMD Zen 4 launch

Post by whispercat » Tue Nov 29, 2022 8:13 am

Steve, I remember you saying that one should wait at least 6 months before buying a motherboard on a new platform in order to allow time for mobo manufacturers to work out most of the initial bugs.

Just wondering if this would apply to CPUs as well?

Thanks.

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Re: New AMD Zen 4 launch

Post by CA_Steve » Tue Nov 29, 2022 10:04 am

...sort of. New CPU releases generally come out with a new motherboard chipset. So, if you are waiting for the mobo firmware to settle out, you are by default waiting for any initial BIOS/driver issues associated with the CPU to settle out.

These days, AMD and Intel are doing staggered releases, bringing the highest priced (highest profit) products out first, then releasing the lesser priced SKUs sometime later. In the latter case, the architecture and features have already been road tested by their higher end brethren. So, if you are looking to buy a non-X version of the R5 7600, it's the same die as the X version with some stuff disabled. Pretty low likelihood of there being a new problem. If you were looking to buy an R3, well that will be the same arch and features but probably in a completely new die, so I'd give it a month to let the early adopters find any issues.

BTW, there was a decent video by Gamers Nexus on Eco mode for the 7950X showing how far AMD turned the core voltage knob to eek out that last bit of performance - hence the high power usage (Intel does likewise). I expect the R5 and R7 do something similar. So, if you go with the X versions for a build today, it looks like you should be able to significantly reduce the power use (and temps) without significantly reducing the performance.

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Re: New AMD Zen 4 launch

Post by CA_Steve » Tue Nov 29, 2022 10:11 am


whispercat
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Re: New AMD Zen 4 launch

Post by whispercat » Tue Nov 29, 2022 8:05 pm

CA_Steve wrote:
Tue Nov 29, 2022 10:04 am
...sort of. New CPU releases generally come out with a new motherboard chipset. So, if you are waiting for the mobo firmware to settle out, you are by default waiting for any initial BIOS/driver issues associated with the CPU to settle out.

These days, AMD and Intel are doing staggered releases, bringing the highest priced (highest profit) products out first, then releasing the lesser priced SKUs sometime later. In the latter case, the architecture and features have already been road tested by their higher end brethren. So, if you are looking to buy a non-X version of the R5 7600, it's the same die as the X version with some stuff disabled. Pretty low likelihood of there being a new problem. If you were looking to buy an R3, well that will be the same arch and features but probably in a completely new die, so I'd give it a month to let the early adopters find any issues.

BTW, there was a decent video by Gamers Nexus on Eco mode for the 7950X showing how far AMD turned the core voltage knob to eek out that last bit of performance - hence the high power usage (Intel does likewise). I expect the R5 and R7 do something similar. So, if you go with the X versions for a build today, it looks like you should be able to significantly reduce the power use (and temps) without significantly reducing the performance.
Thanks so much.

I am seriously looking at the 7900x. I almost pulled the trigger on one for Black Friday as AMD reduced their price on it by approx.$100 CDN. My intention was to get a CPU now and then wait 6 months to buy a motherboard as I remembered your advice. But then I thought, wait, might that advice also apply to CPUs, since both CPU and motherboard actually need to be tightly integrated?

So, I guess I'm back to waiting 6 months for issues to settle out.

Yeah, I was reading somewhere that on eco mode, the upper SKUs 7900x and 7950x go from 170 TDP to around 105 TDP. Temps drop dramatically but performance only drops by about 10%. So a 5.6 GHz boost clock would only be down to around 5 GHz.

CA_Steve
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Re: New AMD Zen 4 launch

Post by CA_Steve » Wed Nov 30, 2022 5:36 am

Most CPU "bugs" post launch are firmware issues, not chip hardware issues. So, that means a BIOS/driver update - not a "we have to change the silicon" problem. The few times buggy silicon have been released into the wild, the problem has been discovered pretty quick and hailed loudly on the tech news sites. It launched Sept 27th, I think. Any h/w bug news out there? It's probably safe to buy the CPU now if you must.

On the other hand, lower pricing....is it just Black Friday pricing or is it here to stay? :)

whispercat
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Re: New AMD Zen 4 launch

Post by whispercat » Wed Nov 30, 2022 6:10 am

I assume any issues with motherboards are also going to be firmware issues (BIOS updates, drivers, etc.). If I'm going to wait for motherboard issues to settle out, I can also wait for any CPU issues to do the same..

But yeah, you never know where the pricing is going to go. If Ryzen releases more Zen 4 SKUs say next summer, hopefully that will put downward pressure on the prices of the first SKUs released this Fall.

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Re: New AMD Zen 4 launch

Post by CA_Steve » Wed Nov 30, 2022 7:34 am

Yep.

I looked at the 5900X pricing, and granted there were tight supplies last year, but it appears there was a price dip for the Nov/Dec time frame, then it went back up until March, then dove. So, short term, the 7900X pricing is maybe as good as it gets.

My 6 mo rule is more of a:
- buy at launch if you like lots of BIOS/driver updates.
- buy 2-3 months out if there haven't been any glaring issues and you don't mind an update in the next month or two.
- buy at 6 mo if you just don't want to deal with updates except on rare occasion.

What mobos were you considering?

whispercat
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Re: New AMD Zen 4 launch

Post by whispercat » Wed Nov 30, 2022 1:18 pm

CA_Steve wrote:
Wed Nov 30, 2022 7:34 am
Yep.

I looked at the 5900X pricing, and granted there were tight supplies last year, but it appears there was a price dip for the Nov/Dec time frame, then it went back up until March, then dove. So, short term, the 7900X pricing is maybe as good as it gets.

My 6 mo rule is more of a:
- buy at launch if you like lots of BIOS/driver updates.
- buy 2-3 months out if there haven't been any glaring issues and you don't mind an update in the next month or two.
- buy at 6 mo if you just don't want to deal with updates except on rare occasion.

What mobos were you considering?
I remember Linus once mentioning that the electronics industry in China slows down between Feb and about May because of Chinese New Year and factories doing inventory during that time, etc. and that this has an effect on pricing.

The mobos I'm considering are the AsRock Taichi, and also Asus Pro Art or Prime. I'd like an ATX board, but so far AsRock only has EATX Taichi boards for AM5. I think Asus has ATX size boards in their X670 line up now, but I'll need to double check.

I'm willing to spend a bit more now because this will be a serious upgrade from what I'm currently using. I'm still running on fumes with a custom computer Mike Chin built for me back in 2009. I've had it for nearly 13 years (an intel system, 2.4 GHz, onboard graphics, P5Q-EM motherboard in an HTTPC case) ). I've had to upgrade the RAM for Windows 10, and replace the Pico PSU which died a month ago, but other than that it's been a very quiet and stable machine for me. My needs have changed a lot, so now I want to splurge on a news system that I hope I can get at least 8 years out of before upgrading again.

It's funny that in 2009 the top end clock speeds were just barely touching the 3 GHz barrier. It took another ten whole years before 3 GHz became the base clock speed. Now after just 3 more years, the base clock speed on many CPUs for both Intel and AMD is over 4 GHz. And next year, Intel should be hitting 6 GHz. I was thinking of upgrading last year to AMD 5900x but then I realized if I just wait another few months I could get a CPU with 1 GHz higher base clock. It seems the pace of increasing clock speeds has really picked up in the last 4 years or so. Anyway, that's my story.

I assume that more AM5 platform motherboards will be coming out in the next several months? I'm hoping AsRock has more Taichi motherboards in the pipeline. Otherwise, I'll go with Asus. I'd like to try Gigabyte some day too.

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Re: New AMD Zen 4 launch

Post by CA_Steve » Fri Dec 02, 2022 9:11 am

whispercat wrote:
Wed Nov 30, 2022 1:18 pm
I remember Linus once mentioning that the electronics industry in China slows down between Feb and about May because of Chinese New Year and factories doing inventory during that time, etc. and that this has an effect on pricing.
Yeah, that's utter nonsense. A mobo mfgr isn't going to limit their revenue stream due to holidays or doing inventory. Heh. They'll have build in finished goods inventory to meet their customer's purchase agreement needs. Pricing fluctuation will be due to: extra strong or weak customer demand, seasonal price drops (eg: Christmas season), tight supply chain driving up prices.
whispercat wrote:
Wed Nov 30, 2022 1:18 pm
I assume that more AM5 platform motherboards will be coming out in the next several months? I'm hoping AsRock has more Taichi motherboards in the pipeline. Otherwise, I'll go with Asus. I'd like to try Gigabyte some day too.
Unlikely. It seems like the number of models have dropped in the last couple of years and typically, the mfgrs announce all the models for a chipset at the same time (when the chipset announcement happens). I wouldn't wait on something new to come out. Focus on the features you like/need.

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Re: New AMD Zen 4 launch

Post by CA_Steve » Mon Dec 19, 2022 9:23 am

Looks like the non-X parts arrive in January. It'll be interesting to see what a "65W" R9 7900 looks like.

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Re: New AMD Zen 4 launch

Post by CA_Steve » Thu Jan 05, 2023 8:15 am


whispercat
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Re: New AMD Zen 4 launch

Post by whispercat » Mon Jan 09, 2023 7:09 pm

Thanks. Yeah, I just skimmed some early reviews. It will be interesting to see whether it would be worth getting a non X and boosting it a little, versus getting an X and stepping it down a little with eco-mode. The non-X might be better value.

whispercat
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Re: New AMD Zen 4 launch

Post by whispercat » Tue Jan 10, 2023 10:19 pm

This was really interesting, and confirmed my suspicions.

https://youtu.be/VtVowYykviM

The 7900 with PBO turns out to be essentially the same thing as the stock 7900x, in terms of performance, thermals, and power draw.. An exception is Adobe Premier, where the 7900x still performs a bit better than the 7900 with PBO.

So it boils down to a choice between getting a 7900x and stepping it down with eco mode to save thermals and power when not needed, or getting a 7900 and boosting it with PBO when needed. There's almost no difference, except for the price, with the 7900 being cheaper.

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Re: New AMD Zen 4 launch

Post by CA_Steve » Wed Jan 11, 2023 12:31 pm

yep!

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