Codenamed Arthur, the PowerPC 750 was offered in 233, 266, 300, or 333 MHz configurations on the 1997 Power Macintosh G3 and 233 MHz on the 1998 iMac G3. The 750 improved on the 603e with a faster 60x system bus (66 MHz), larger L1 caches (32 KB instruction and 32 KB data), a second integer unit, an enhanced floating point unit, and higher core frequency. It also added dynamic branch prediction and a 64-entry branch target instruction cache (BTIC).
The Perseverance rover is actually using a radiation-hardened processor based on the PowerPC 750 called the RAD750. Originally released in 2001, the RAD750 has 10.4 million transistors and operates at 110 to 200 MHz. It's manufactured by BAE Systems using either a 250 or 150 nm process and has a die area of 130 mm². The CPU itself can withstand 200,000 to 1,000,000 Rads and temperature ranges between −55 and 125 °C.
Pricing for the RAD750 is significantly higher than you might expect. The processor costs in excess of $200,000 USD mainly due to radiation hardening revisions to the PowerPC 750 architecture and manufacturing, stringent quality control requirements, and extended testing of each processor chip manufactured. [W]
“A charged particle that’s racing through the galaxy can pass through a device and wreak havoc,” James LaRosa at BAE Systems told NewScientist. “It can literally knock electrons loose; it can cause electronic noise and signal spikes within the circuit.”
Most importantly, NASA uses the RAD750 because it's reliable.
“Compared to the [Intel] Core i5 in your laptop, it’s much slower…it’s probably not any faster than your smartphone,” Matt Lemke, NASA’s deputy manager for Orion’s avionics, told The Space Review back in 2014. “But it’s not about the speed as much as the ruggedness and the reliability. I need to make sure it will always work.”
The RAD750 powers around 100 satellites orbiting Earth that provide GPS, imaging, weather, and military data. LaRosa says not one of those has failed.
You can learn more about the Perseverance rover at the link below...