Externally, the iMac Intel 27″ EMC 2639 looks identical to the previous generation, but the interior specs have been upgraded:
3.2GHz quad-core Intel Core i5 processor (Turbo Boost up to 3.6GHz) with 6MB L3 cache
NVIDIA GeForce GT 755M graphics processor with 1GB of GDDR5 memory
PCIe flash SSD available
The AirPort/Bluetooth card, conforming to the 802.11ac Wi-Fi standard, still clings to the back of the logic board — making replacement no easier than before.
Not the first Mac to get updated with the new ac standard, we expected to see some similar hardware as in the refreshed MacBook Airs from earlier this year.
Chips off the old new block:
Broadcom BCM4360KML1G 5G WiFi 3-stream 802.11ac gigabit transceiver—as expected, this is the same chip driving the ac Wi-Fi in the 11″ and 13″ MacBook Air
Three Skyworks SE5516 : dual-band 802.11a/b/g/n/ac WLAN front-end modules
Broadcom BCM20702 single-chip Bluetooth 4.0 HCI solution with Bluetooth Low Energy (BLE) support
As is now standard across all new iMacs, the new iMac 27″ features support for PCIe-based flash storage. This is a pleasant surprise compared to last year’s 21.5″ model, when we were left sorely disappointed by unpopulated solder pads on our low-end logic board.
According to Apple, the inclusion of PCIe flash storage allows for up to 50 percent faster speeds than the previous generation.
The Fusion Drive option combines the large storage capacity of a hard drive with the high performance of flash to deliver shorter boot times and faster access to apps and files.
Apple’s iMac refresh included some sneaky changes to the 21.5″ model, and we were more than a little perturbed to discover a soldered CPU.
Thankfully, its 27″ big brother was saved from the same fate, and power users will still be able to upgrade their processor without a reflow oven
As advertised, the iMac 27″ now sports a fancy new graphics processor:
NVIDIA GeForce GT 755M GPU
Four SK hynix H5GQ2H24AFR 256 MB GDDR5 SGRAM ICs make up the 1 GB of graphics RAM
iMac 27″ EMC 2639 Repairability Score: 5 out of 10 (10 is easiest to repair)
RAM is user-replaceable without opening the case, thanks to the rear access door.
You can still replace the hard drive and CPU inside this machine, albeit with some adhesive cutting.
Components are modular and fairly easy to remove.
Budget-minded folks now can add a second hard drive to the base iMac because the Fusion Drive connector is no longer missing from the logic board.
The glass and LCD are fused together, and there are no more magnets holding the glass in place.
You’ll have to masterfully peel off the old double-sided sticky tape and apply new tape in order to reseal this iMac into original condition