RAM-BO
Let’s take a look at the memory first. In the PC set-up, we have 8 gigs of common DDR3 RAM, but Sony has somehow crammed the same amount of GDDR5 RAM into its PS4.
GDDR5 is primarily used in graphics chips. It’s not something you see used as system RAM at all.
For instance, the nVidia “Titan” GPU, which costs $1000 by itself, has just 6GB of GDDR5 RAM, and that’s still all reserved for the GPU. You’ll be hard-pressed to find any PC with GDDR5 plugged directly into the motherboard rather than sitting on the graphics card. This just isn’t how PCs work at the moment, though that will likely change.
GDDR5, while suffering from slightly higher latency, offers a substantial bandwidth boost over DDR3, and given the make-up of the integrated CPU/GPU chip in the PS4 this will translate to a substantial performance boost.
One Chip to rule them all
Next up we have the CPU/GPU configuration.
Again, what Sony has done with the PS4 is something that PC builders simply cannot do yet. PC’s come with two separate chips connected over a PCI-E chipset.
The PS4, on the other hand, houses an integrated CPU/GPU custom AMD chip—the “Jaguar” CPU is not available for purchase yet and the GPU side of the equation is said to be similar to AMD cards running in the $200 price-range. The secret weapon here isn’t either the 8-core CPU or the GPU, but rather how the two are paired.
Both the processor and the graphics card are built into the same chip and both tap into that 8GB of DDR5 memory at once—it’s a “unified memory” setup as opposed to the system your PC uses, with the CPU utilizing your DDR3 system memory and your GPU harnessing the more robust GDDR5.
What does this mean? Basically it means that the two chips will be able to communicate with one another much faster and more efficiently than in a traditional PC set-up. Combine this with the high-bandwidth GDDR5 memory and the fact that much of the traditional CPU tasks will be offloaded to the GPU, and you have a machine that you simply cannot compare to a modern PC.
