Why is PC RAM only 64-bit?

[Track]

They keep trying to highten the clock speed to increase the bandwidth, but why not increase the bus width to something over 64-bit like they do on graphics cards? There hasnt been 64-bit RAM on graphics cards for over 3 years.

 

[Mondoman]

Dual-channel mode accomplishes the same increased throughput without having to come up with a new RAM module design.

 

[derek2006]

I am not sure of this at all but isn't the upcoming DDR3 more than 64 bit?

 

[Track]

Dual-channel mode accomplishes the same increased throughput without having to come up with a new RAM module design.

How does that work? Then u just have two sticks working at 64-bit when we have cards working at 512-bit already.

 

[chocobocorey]

They keep trying to highten the clock speed to increase the bandwidth, but why not increase the bus width to something over 64-bit like they do on graphics cards? There hasnt been 64-bit RAM on graphics cards for over 3 years.

i duno. well have to wait for jack to school us on this one.

 

[niz]

They keep trying to highten the clock speed to increase the bandwidth, but why not increase the bus width to something over 64-bit like they do on graphics cards? There hasnt been 64-bit RAM on graphics cards for over 3 years.

Jeez its been hard enough to get people to move off 32-bit OS's to 64 bit. I'm running 64-bit XP and Linux but I bet most people here still are running a 32-bit OS and thats amongst a supposedly technically aware audience.

I suppose one big reason is the armchair experts here who have never run a 64-bit OS but think they should advise everyone about it keep spreading misinformation that 32-bit software won't work on 64 bit OS's which is total baloney.

 

[derek2006]

It doesn't have the same throughput as gpu's but it is increased by 2 fold. CPU's don't use that bandwidth anyway that's why there really isn't all that performance increase between single and dual channel. So there is not reason.

I run a 32 bit OS because I don't feel like buying another license for a less stable OS.

 

[Heyyou27]

When are you going to stop posting?

 

[Bluefinger]

Because for PC RAM there's no need for such high bandwidths. Besides, it limitations in the Northbridge controllers or IMCs, along with RAM technology which prevents data channels over 64-bit to be implemented. DDR3 will come with wider bandwidths, but its not gonna matter that much anyway, since the latency increases will inevitably dumb the effect of the improvements.

 

[Mondoman]

Dual-channel mode accomplishes the same increased throughput without having to come up with a new RAM module design.

How does that work? Then u just have two sticks working at 64-bit when we have cards working at 512-bit already.
As others have pointed out, since current and near-future CPUs can't even handle current dual-channel memory throughput, there's not much point in increasing the memory bandwidth further.
Remember also that GPUs tend to do repetitive processing in parallel on vast amounts of data, while CPUs tend to do more complicated processing on lesser amounts of data. Thus, typical GPU operation is much more sensitive to memory bandwidth than typical CPU operation.

 

[Track]

So CPUs arent good enough and thats why they have to keep bandwidth low at 64-bit bus width?

 

[Mondoman]

Not really, IMHO it's pretty much because it's not worth the effort (gains would not be major). GPUs and CPUs do different things and have very different memory access profiles.
To make an analogy, in the US, postal delivery vehicles are specially made with the driver's side being on the right. This greatly improves the efficiency of the postal carrier, as he/she spends most of his/her time driving along the right curb, accessing mailboxes and buildings on the right. Of course, that doesn't mean that all cars in the US would work better with the driver's side on the right. In the specialized postal delivery case, it helps greatly, but wouldn't in the general case.