Raspberry Pi 5

Raspberry Pi 5 的消息出來了:「Introducing: Raspberry Pi 5!」。

價錢是 $60 (4GB RAM 版本) 與 $80 (8GB RAM 版本),目前看起來是 pre-order 階段。

Today, we’re delighted to announce the launch of Raspberry Pi 5, coming at the end of October. Priced at $60 for the 4GB variant, and $80 for its 8GB sibling, virtually every aspect of the platform has been upgraded, delivering a no-compromises user experience.

其中一個大賣點應該是效能了,宣稱與 RPi4 相比,CPU/GPU 效能是以前的兩倍到三倍,記憶體與 I/O 的頻寬也加倍了,所以應該是所有應用都會變快不少:

Today, that effort bears fruit, with the launch of Raspberry Pi 5: compared to Raspberry Pi 4, we have between two and three times the CPU and GPU performance; roughly twice the memory and I/O bandwidth; and for the first time we have Raspberry Pi silicon on a flagship Raspberry Pi device.

等到後續出貨應該就會有資料可以看了,不過從時脈就可以看出一些重點,上一代還是 1.5GHz (或是後來更新的 1.8GHz),這一代拉到 2.4GHz 了:

2.4GHz quad-core 64-bit Arm Cortex-A76 CPU

而後續也提到,在相同的 loading 吃電量比 RPi4 低,但因為 boost 的關係,瞬間最高吃電量從以前 RPi4 的 8W 變到 RPi5 的 12W:

Raspberry Pi 5 consumes significantly less power, and runs significantly cooler, than Raspberry Pi 4 when running an identical workload. However, the much higher performance ceiling means that for the most intensive workloads, and in particular for pathological “power virus” workloads, peak power consumption increases to around 12W, versus 8W for Raspberry Pi 4.

但也因為這樣,如果你拿 15W 的 USB-C 充電器時,他的 USB port 就只能提供 3W 的功率了 (剛好就是他提到的 5V/600mA):

When using a standard 5V, 3A (15W) USB-C power adapter with Raspberry Pi 5, by default we must limit downstream USB current to 600mA to ensure that we have sufficient margin to support these workloads. This is lower than the 1.2A limit on Raspberry Pi 4, though generally still sufficient to drive mice, keyboards, and other low‑power peripherals.

如果要能夠讓 USB 可以供應足夠的功率 (像是外接的機械硬碟這種會吃比較多電的設備),需要使用 5V/5A 的充電器。

但這邊提到 RPi5 firmware 在偵測到 5V/5A 的充電器時會提高限制,而不是提到 USB PD,所以可以預期是特規?

For users who wish to drive high-power peripherals like hard drives and SSDs while retaining margin for peak workloads, we are offering a $12 USB-C power adapter which supports a 5V, 5A (25W) operating mode. If the Raspberry Pi 5 firmware detects this supply, it increases the USB current limit to 1.6A, providing 5W of extra power for downstream USB devices and 5W of extra on-board power budget: a boon for those of you who want to experiment with overclocking your Raspberry Pi 5.

供貨的部分反而沒有聊到太多,但 RPi4 最近的供貨還算可以,所以可以預期 RPi5 應該不會太差?

Leave a Reply

Your email address will not be published. Required fields are marked *