Understanding why Xbox One doesn't need GDDR5 RAM

[Eddie_Raja]

disolitude said:

Everyone knows GDDR5 RAM is more beneficial for GPU memory. System memory however is actually better off with DDR3 RAM due to sligtly lower latency. 

 

In terms of next gen console GPUs, below are the specs:

PS4 GPU Cores - 1152

Xbox One GPU Cores - 768

and

PS4 Peak Shader Throughput - 1.84 TFLOPS

Xbox One Peak Shader Throughput - 1.23 TFLOPS

 

Xbox One GPU has 33% less cores and 33% less peak shader throughput. Due to this, it needs less video bandwidth than PS4.

This leads us to video RAM:

PS4 Video Memory Bandwidth - 176 GB/s

Xbox One Video Memory Bandwidth ( DDR3 + sRAM cache) - 102 GB/s

 

Xbox One would not benefit at all from having 176 GB/s GDDR5 bandwidth due to lower GPU throughput. If they gave the Xbox more GPU cores it would be a different story however its RAM bandwidth is perfectly proportional to the GPU performance.

Its no secret that Xbox One has a less powerful GPU, but because it skipped on GDDR5 memory it can enjoy better system RAM, much less power consumption and heat, and cheaper manufacturing cost.

Just an FYI to those that say Xbox One is at a disadvantage for not having GDDR5 RAM.

Time to educate: 

1) GDDR5 uses less energy and produces less heat.  The DDR3 is not "better system RAM."  Yes due to lower speeds it has tighter timings, but speed matters much more.  Example: My 2133 MHz DDR3 has 50% less tight timings than my old 1600MHz RAM, but it still performs better at EVERYTHING.

2) The 7750 has 512 Cores and runs at 900 MHz compared to the X1's 800 MHz.  Before RAM is considered it should be about 30% weaker.  Most 7750's use GDDR5, but there are cheap versions that use DDR3.  The DDR3 version performs half as well.  

RAM feeds the core, and the faster it is -> the faster the core can process.  Even with a miniscule amount of SRAM, the system will be majorly bottlenecked.  Prepare for a lot of pop in!