[bayindirh]

When I see the term TDP, I remember what I have read in the "Thermal Design Document" of Intel Core2Quad Q6600 and the family it belongs:

> The thermal solution bundled with the CPUs is not designed to handle the thermal output when all the cores are utilized 100%. For that kind of load, a different thermal solution is strongly recommended (paraphrased).

I never used the stock cooler bundled with the processor, but what kind of dark joke is this?

[johncolanduoni]

Most states of “100% utilization” as you’d see in `top` are not 100% thermal output or even close. Cores waiting for memory accesses count as utilized in the former sense but will not produce as much heat as one that is actually using the ALU etc. That’s why special make-work like Prime95 is used for stress testing overclocking/thermals: it will saturate the cores with enough unblocked arithmetic work to generate more heat than having 1000 browser tabs open does.

[account42]

You're not going to get anywhere near full thermal load with just integer arithmetic either - you need to saturate the floating point units for that.

[kokada]

This is more how I think too: using a cooler that supports your CPU TDP is generally fine because most people will not run a CPU 100% for an extended amount of time. But in this case they seem to be running the CPU 100% for an extended amount of time AND are using an under-spec'ed cooler (even if it is just by 5W).

You don't even need to change the actual cooler since for AMD CPUs you can pretty much customize the TDP whatever way you want, and by default they run well above their efficiency curve. For example, my 7600X has a default TDP of 105W but I run it in Eco Mode (65W) with undervolt and I barely lose any performance. Even if I did no undervolt, running the CPU in Eco Mode is generally preferable since the performance loss is still negligible (~5%).

[bayindirh]

For a general purpose system, this line of thinking makes sense. However, the desktop system in question was built to be daily driven and support some high performance code research, so it had to endure some serious loads for a desktop computer.

I went the other way and overspecced the CPU cooler and added some silent but high CFM capable fans on the system. The motherboard I got was able to adjust all fans depending on the system temps, so it scaled from a very silent desktop to a low-key space heater automatically under load.

Instead of undervolting the processor, I was using a tweaked on-demand governor on the system which stuck to lower power levels more than usual, so unless I was doing software development and testing things, it stayed cool and silent.

BTW, by 100%, I'm talking about completely saturating the CPU pipeline. Not pseudo 100% where CPU reports saturation but most of the load is iowait.

[cogman10]

Man that was a beast of a CPU back in the day.

The Conroe Intel era was amazing for the time.

[keanebean86]

That was such a fun time to be into hardware. For years Intel had the money and relationships to keep the Pentium 4 everywhere even though AMD had the better product. The P4 might edge ahead in video rendering but the Athlon would win overall and use less power.

Then Conroe launched and the balance shifted. Even the cheapest Core2Duo chips were competitive against the best P4s and the high-end C2Ds rivaled or beat AMD. https://web.archive.org/web/20100909205130/http://www.anandt...

AND those chips overclocked to the moon. I got my E6420 to 3.2ghz (from 2.133ghz) just by upping the multiplier. A quick search makes me think my chip wasn't even that great.

[cogman10]

Absolutely. Intel was also keeping up the tick-tock processing. I could be misremembering, but it seemed like every tock intel was getting something like 20% improvements over the last tock. It really wasn't until ~Haswell that that slowed down and continued to slow down to basically nothing. I think Kaby Lake IIRC was the last major performance jump from intel. Everything else has just been incremental changes.

[bayindirh]

One of the reasons that Intel only shipped 5% incremental updates was AMD was basically non-existent due to both Intel pressuring them and AMD has done a massive mistake with bulldozer/piledriver architecture.

They vastly underestimated how much a single FPU would be bottleneck on a multicore/SMP processor.

Then AMD took things personal and architected Zen/EPYC. The rest is history.

[cogman10]

Certainly, and by that time Intel just sort of dropped all the balls. They were already struggling to do die shrinks and it seems like they simply lost all their ability to develop the architecture.

That had maybe happened years earlier. The thing about Conroe is, IIRC, its ancestry came from the P3 and Intel's mobile CPU designs. P4 was steady evolutions on the Netburst architecture. The years of improvements to conroe were mostly just incremental changes and porting over features from Netburst (such as hyperthreading). Once that all played out, intel really didn't have anywhere else to go or plans on how to evolve the architecture. They fell back on the same old "let's just add wider SIMD instructions (AVX)".

I also seem to recall that intel made fab bets that ultimately didn't pay off. Again, IIRC, I believe they were trying to use the same light lithography (230nm light?) rather than going into UV lithography. That caused them to dump a fair bit of money fabrication that never really paid off.

[bayindirh]

Buying parts for that particular desktop was quite fun:

    - Me: Can I get a Q6600?
    - Seller: But, that's... Quad core?
    - Me: Yes, I'll have it.
    - Seller: OK. RAM?
    - Me: I'll get OCZ Flex-XLC Hybrids. 1GB.
    - Seller: *Gives one*
    - Me: I'll get four.
    - Seller: ?
    - Me: Yes, four please.

Motherboard was an MSI P35 Platinum. Fun times.

[lofaszvanitt]

I always used the stock cooler, because it's quiet and nothing uses the cpu to its fullest :).