RTX 4070 終於解禁，NVIDIA 僅以約 200W 的功耗提供無限接近 RTX 3080 的性能水平，使 RTX 4070 成為最便宜的 RTX 40 系列顯示卡。RTX 4070 之中不少高階型號均使用 12VHPWR 作為電源輸入接頭，哪怕 TGP 只有 200W ~ 220W。可是在 NVIDIA 自家的創始版本上，卻出現了疑似專為 12VHPWR 接頭而設的導熱貼，與 IGORSLAB 近日關於 12VHPWR 接頭溫度的研究和建議不謀而合。
200W 的 RTX 4070 配 12VHPWR 毫無壓力
IGORSLAB 提出在 12VHPWR 接頭附近的元件有一定的發熱量，使 12VHPWR 接頭溫度上升，也證實在 12VHPWR 接頭的 PCB 範圍加上導熱貼後，能夠有效降低 12VHPWR 接頭的溫度。
NVIDIA 被發現在剛剛解禁的 RTX 4070 FOUNDERS EDITION 上，使用了導熱貼覆蓋 12VHPWR 接頭下方的電流檢測電阻 (SHUNT RESISTOR)，將熱量導向至金屬背板上。NVIDIA 未有解釋相關決定的原因，就筆者觀察亦未有其他廠商在相同位置上加上導熱貼為電流檢測電阻降溫。
200W 的顯示卡 NVIDIA 也不敢掉以輕心，盡全力降低 12VHPWR 接頭的溫度，甚至容許非公版使用傳統 PCI-E 8-PIN 設計。不知道 NVIDIA 又是否為新一批的 RTX 4090 / 4080 FOUNDERS EDITION 加入導熱貼呢？
…it is my pad mod for the 12VHPWR connection, which I had already thematized and also implemented with the RTX 4090! And NVIDIA has even gone further and placed the shunt (as recommended) on the back (see PCB teardown) and cools it (under the pad) at the same time. Commendable, but at these low currents it is completely unnecessary, as we will see. On the RTX 4090 or RTX 4080, something like this would have made much more sense and been more appropriate. But maybe someone can open his new RTX 4090 FE and have a look. In the case of the GeForce RTX 3080 FE, it was also included in the current production… 🙂 IGORSLAB
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