Could this be the last PC I ever own?

円管内乱流速度分布のDSMC計算の改良が終了したので，今年のもう一つの目標である threadripper 9980X のPCの取得に舵を切りました．今年初めから続くPCメモリ等の高騰（５倍になる場合もある）により，自作をしても組み立て済みのもの購入してもを価格的にはあまり差はないことと，自身の左目が見えにくくなっていることもあるので，自作はあきらめ，完成品を購入することにしました．threadripper 9980X の品薄感もあって，注文してから届くまでに２週間以上かかりましたが10月末には手に入りました．7年前に購入した threadripper 3990x は，128 threads のCPUでしたが，Windowsの制約により，一つのJOBでは64threadsまでしか並列計算ができなくて，やむをえず，計算領域を2つに分けて128theradsを利用するという面倒な手順を踏んでいました．Windows11が発売されて64threadsの縛りがなくなり，新しいマザーボードも登場して，いよいよ128threadsの並列計算を心置きなく実行できると高をくくっていたのですが，神様も簡単には微笑んでくれません．グーグルAIに相談しながらマザーボードのBIOS設定を変更してもなかなかうまくいかず，挙句は，グーグルAIに文句を言う始末．喜寿を迎えた老人は，物事がうまくいかないとすぐにふてくされて，ソファーにゴロンと横になってしまう．しかし，横になってウトウトはしていても頭の中で思考が止まることはありません．私の50年以上にわたる研究生活で得た最大の教訓は，「今日はダメでも，いずれは解決する」というものです．タスクマネージャーでは相変わらず，2つの計算グループに分けられているものの，パフォーマンス表示では，一つのJOBで64threadsを超える点灯の確認ができて，いよいよ光が見えてきました．実際に，100threadsまでは計算速度の増加も確認できたのです．100threadsを超えたあたりで急に計算速度が遅くなってしまいますが，まあでも，ここまでくれば，いよいよ私のずる賢さが発揮されるときです．私のプログラムのどこかに不完全な箇所があるに違いない．そしてそれが見つかって，128threadsでの高速並列計算が実現できました．やれやれ．新しいPCを手に入れてから満足な結論が出るまでに10日間かかりました．その間．私の脳細胞のシナプス結合はまた強化されたので，これでボケるのを遅らせることが出来ました．あと10年は生きられるかな．でも10年生きたら，また新しいPCが欲しくなってしまうけど．計算速度の比較では，Ryzen_9 9950X3D の 2.5～3倍，消費電力は約3倍，かかった費用は約5倍，自己満足度の倍率は，表現がなかなか難しい．なお，PC冷却用のファンの音がうるさいので，本年中に何とかしたい．７年前の 3990x のときは，簡易水冷をnoctuaの空冷に替えてうまくいったけど，今回はどうするか．悩みはなかなか尽きません．

Having completed improvements to my DSMC (Direct Simulation Monte Carlo) calculations for turbulent velocity profiles in a circular tube, I shifted my focus to another goal for this year: acquiring a PC equipped with a Threadripper 9980X. Due to the sharp rise in the cost of components like PC memory－which in some cases has increased fivefold－there is now little price difference between building a PC from scratch and buying a pre-built one. Furthermore, as my vision in my left eye has deteriorated, I decided to forgo building it myself and opted for a ready-made system. The Threadripper 9980X was in short supply, so it took over two weeks to arrive, but it finally reached me at the end of October. My previous machine, purchased seven years ago, featured a 128-thread Threadripper 3990X; however, due to Windows limitations, a single job could only utilize up to 64 threads for parallel computation. This forced me to go through the cumbersome process of splitting the computational domain into two parts to make use of all 128 threads. With the release of Windows 11 and the arrival of new motherboards, I assumed I would finally be able to run 128-thread parallel computations without any constraints－but as it turns out, fate doesn’t always smile so easily. I struggled to get things working, even after consulting with Google’s AI to adjust the motherboard’s BIOS settings－at one point, I even found myself complaining to the AI! At 77 years old, whenever things don’t go my way, I tend to get sulky and flop down on the sofa. Yet, even as I lie there dozing off, my mind never stops working. The greatest lesson I’ve learned over my 50-plus years in research is this: “Even if things don’t work out today, they will eventually be resolved.” Although the Task Manager still shows the workload split into two separate groups, the performance monitor indicates that a single job is now utilizing more than 64 threads－at last, I can see a light at the end of the tunnel. In fact, I was able to confirm an increase in computational speed up to 100 threads. Beyond that point, the speed dropped off sharply－but this is precisely where my cunning comes into play. There had to be a flaw somewhere in my program; once I tracked it down, I managed to achieve high-speed parallel processing using 128 threads. Phew! It took ten days from the moment I got the new PC until I reached a satisfactory conclusion. In the process, the synaptic connections in my brain got a workout－a great way to stave off cognitive decline! Maybe I’ll live another ten years? Though, if I do, I’ll probably just end up wanting another new PC. Comparing the performance: it’s 2.5 to 3 times faster than the Ryzen 9 9950X3D, consumes about three times the power, and cost roughly five times as much－as for my level of self-satisfaction, well, that’s hard to quantify. Also, the cooling fans are quite noisy, so I’ll need to address that sometime this year. Seven years ago, with my 3990X, I solved a similar issue by swapping the AIO (all-in-one) liquid cooler for an air cooler from Noctua－I wonder what I should do this time? The dilemmas just never seem to end.