DDR3 (+XBOX One
) vs GDDR5 (+Playstation 4
** Warning reading this comment might involve learning something new **
So the "console wars" are back on and the spec sheets are released and people are up in arms. There are many controversial topics to talk about but instead of trying to incite a mini fight in the comments section of this post, I thought I would talk about something that has a lot of people confused that I think I can clear up in a very neutral (and truthful) way.
These are the most common "arguments" I hear in regards to the next gen consoles RAM:
1: "PS4 has super amazing GDDR5 RAM!! Xbox only has DDR3 which is clearly inferior."
2. "Dude... there isn't even enough difference in the types of RAM to make any real difference anyway."
I am going to explain why both of the above comments are very wrong, and hopefully in the process give each side a mutual respect for the hardware engineers both at Sony and Microsoft (as they are all very smart I am sure).
"5 is bigger than 3, so GDDR5 is better than DDR3! Am I right or am I right?" Sorry, but you're wrong. In order to understand the difference between DDR3 and GDDR5, you will have to know two basic concepts: Latency and Bandwidth. And in order to explain them more easily, I am going to enlist the help of an analogy.
Latency is best described as the response time. Imagine you are tasked with pouring water from a bucket down a pipe and out the other side. You want to get this task done as quickly as possible and there is good news, you get to choose the pipe you are using. Latency would be the equivalent to how long your pipe is. The longer the pipe, the more time it takes for water to get to the other side. So logic dictates that the shorter the pipe, the quicker you can get the water out the other side! That is simple enough, so what is bandwidth? Well there is another way to get water more quickly through the pipe, and that is increasing the width of the pipe. The wider the pipe is, the more water you can pour at once. So to complete this task as quickly as possible, it would make sense to have a really short (low latency), really wide (high bandwidth) pipe.
Here is where the trouble comes, in the world of RAM, you must sacrifice one for the other. So the big difference between DDR and GDDR is GDDR has much higher latency than DDR, but also has a much higher bandwidth. So which is better? The answer is, "It depends". If you think about the pipes for a minute, would it be better to have a long wide pipe, or a short skinny one? Well, it depends upon how much water you need to pour down the pipe. A small amount of water will go down the shorter pipe faster, but a large amount will go down the longer/wider one faster. Now in order to make the analogy resemble computing a little more closely, we need to make one slight alteration to the analogy. Now imagine you have a bunch of buckets of water that need to go down the pipe, and you have to wait for each one to finish draining before you start on the next bucket. Now which pipe is better is even more blurred as it can take quite a while to pour a bunch of small buckets down the long pipe, and on the other hand it can take a while to pour just one large bucket down the skinny short pipe.
If you haven't figured it out by now, the pipe itself is the RAM, and the buckets of water is the data that has to be loaded into RAM. So if you need to load a large amount of data into RAM all at once, or are constantly switching out large amounts of data, then GDDR5 is going to be a much faster solution. If however, you are constantly loading small bits of data into RAM, then DDR3 will be faster.
Now comes the opinionated section of my post. You can take Microsoft's and Sony's choice of RAM any way you want but personally I think it shows that the two companies have a different view for the future of their systems. There is virtually one place where having GDDR5 RAM is going to out perform DDR3, and that is rendering graphics. Sony is basically sacrificing the efficiency of all the small operations that the PS4 will do in order to get a boost during gameplay. This makes sense considering their seemingly strong refocus on gaming. Microsoft on the other hand is focusing on making their system the center of entertainment. I imagine they will have a much more feature rich (and also resource intensive) operating system and it wouldn't make sense to sacrifice efficiency on every level just to get that boost in game rendering for a system like this.
Hope that helps!