Product ReviewsIntel Xeon X5355 2.66GHz Quad-Core (HH80563KJ0678M) Processor

Doubled Mac Pro 1,1 speed

Upgraded my old quad core Mac pro 1,1 with these and it has doubled the performance. Coupled with 28gb of ram and an ati radeon 5770. Also upgraded the OS to El capitan. Now I can delay upgrading to latest technology.Read full review...

Verified purchase:  Yes | Condition: pre-owned | Sold by: 1990miamihurric...

Great upgrade!

We opted to upgrade all of our Mac Pro 1,1s to these CPUs and they run Great! We installed El capitan and now these systems work on par with a good Quad i5, but we have the expansion slots for awesome video cards and other peripherals!Read full review...

Verified purchase:  Yes | Condition: pre-owned | Sold by: www.mashek.com

Good product if you can find it at a reasonable price.

Bought these because I wanted a few more cores to support running more virtual machines on my server at the colo (data center). The Woodcrest 5160 CPUs I had were fine, but the X5355 let me go from 4 cores to 8 in the same server, and more cores offset the slight loss of clock speed. Unfortunately HP never updated the BIOS to support the 54xx Harpertown CPUs, even thought the chipset supports it, so finding these X5355 Clovertowns at a reasonable price was my best option.Read full review...

Great value way to improve performance of early Mac Pros (2006 models)!

I got a pair of these to replace standard processors in a MacPro 1,1 - which is designed to allow the processors to be upgraded. There are several "how to do this" reports on the web, and the upgrade itself was pretty easy to do. And the results completely as expected - CPU performance roughly doubled (Geekbench went from 5400 to 10221).

The processors cost a fortune 'new' but there are many around from refurbished cpu shops, and the prices on these are pretty good currently.Read full review...

x5355 with MacPro1.1 and now is 2.1

The cpus x5355 working NICE now my MacPro 1.1 go to 2.1 and double the performance after upgrade with this CPUs, Firmware and reset RRAM - working like new with double speed. Thanks

Verified purchase:  Yes | Condition: pre-owned | Sold by: wychoi63

Arrived quick, performs well

Arrived very quickly, and the install was successful. All 8 cores are recognized, and the machine performs notably faster in CPU heavy workloads.

Verified purchase:  Yes | Condition: pre-owned | Sold by: ssinc1500

Awesome deal, great packaging.

Decided to upgrade my Mac Pro 1,1 and did some research into how to swap CPUs. These were incredibly well packaged and numbered.

Working great, but would recommend downloading program called Macs fan control to allow control of internal fans since CPUs generate more heat.Read full review...

Verified purchase:  Yes | Condition: pre-owned | Sold by: wychoi63

Upgrade for Mac Pro

Turned my Mac Pro 1,1 into a 2,1 fairly easy to replace but make sure you get the firmware tool. Other than that, great upgrade to a powerful machine!

Verified purchase:  Yes | Condition: pre-owned | Sold by: www.mashek.com

Fantastic Purchase!

Purchased these matched pair processors to breath new life into my aging 2006 Mac Pro and all I can say is magic. Work flawlessly and saw a double point increase in overall baseline scores.

Verified purchase:  Yes | Condition: pre-owned | Sold by: rakicomputers

Cheap way to add life to old MacPro

Bought these chips used as a cheap way to do an unsupported upgrade to a Mac Pro 1,1. Followed a youtube video to do the upgrade. It isn't an upgrade to be attempted if you aren't patient and adventurous. Doubled the speed and added new life to the old computer.Read full review...