What is the difference between 128-bit and 256-bit?

[wl589]

I am looking at two cards and the 128 bit card has a lot better stats but it's 128-bit not 256 bit, so I am wondering what is the difference? Is the difference more important than the other specs?

 

[omnisome]

Not really an important spec..
All the modern cards tend to have 128bit, especially AMD

 

[JDFan]

It is no more and no less important than other specs --- figure the Memory speed - bus bit width and type of RAM (ddr3 vs. DDR5 etc.) all combine to give you the total memory throughput that the card can sustain -- so a card with higher speed DDR5 RAM and a 128 bit bus can be faster than a 256 bit bus card based on slower speed DDR3 ram - but if all other things are the same then a 256 bit bus is better than a 128 bit bus since it can handle twice as much info per clock cycle - but just having a 256 bit bus does not necessarily mean it is a better card. You have to consider the combination of specs to see what the total memory throughput is.

 

[bystander]

What cards are you comparing? Benchmarks are the only real way to compare. There are too many other aspects of cards to look at their stats.

 

[bertimus]

The difference between 256 bits and 128 bits is 128 bits 😛

In all reality, the bit count that they are referring to is the number of binary digits that the card reads per line of machine ISA code. Generally, having more bits is better, but you probably won't ever know the difference in use between the two.

 

[jjb8675309]

it all depends on what cards you are comparing a 128 bit 5770 is faster than a 4850 256 bit, another example of this is the 448bit gtx 260 is much slower than the 5870 (256 bit) and really the gtx 260 is similar performance to a 5770, with no dx11 of course so it all depends on what cards specifically you are comparing. Different companies respectively run on different architecture and processes so an nvidia processing core does not equal an amd stream processor. Overall just look at some benchmarks to see what is what.

 

[mrjericho1991]

gtx 260 is better than hd 5770 and is on par with hd 5830,i ve seen alot of benchmarks where gtx 260 always beats hd 5770 cuz it has better bandwidth,better bus and also physx is replace of dx11,if i would be you i would go with gtx 460,it is good investment for two years.

 

[iam2thecrowe]

what you need to look at when comparing bits is total bandwidth. a 128 bit interface at 1000mhz has the same bandwidth of a 256bit interface at 500mhz. Newer cards that use 128bit ram often use ddr5 which has 2 x the bandwidth per clock cycle of ddr3 or 2, therefore cancelling out the fact that they have 128bit vs a ddr2 or 3 256 bit card.

 

[jjb8675309]

gtx 260 is better than hd 5770 and is on par with hd 5830,i ve seen alot of benchmarks where gtx 260 always beats hd 5770 cuz it has better bandwidth,better bus and also physx is replace of dx11,if i would be you i would go with gtx 460,it is good investment for two years.

again a load of crap from you jericho gtx 260 may be a frame or two better in some games but by no means is it "better" then the 5770, look at some benchmarks before you start foaming at the mouth about nvidia, and yeah for that matter it is close to the 5830 which is practically a 4890, but still not as powerful, so really your argument and comment is crap and take away from my point that the specs alone do not mean anything especially if the chip itself is not powerful enough to utilize the memory buffer or bitrate. The thing that angers me is how you jericho always comment illogically and have zero thought to what you are saying, i have seen you countless times on here with qoutes like "the gtx 465 is better then the 460" or "the gtx 295 is the fastest card available" you sputter nonsense, hopefully no one listens to this clown. Besides that I was comparing the 5770 128 bit to the 5870 if you actually could read and comprehend english writing then you wouldnt have made such an ignorant, irrelevent, and illogical comment, save your nvidia gloating for igns message boards please, jericho you are worthless..

and besides that looking at 2 benchmarks where the gtx 260 is faster doesnt mean jack, some games the 260 would win out (ones that are optimized for nvidia) and other the 5770 would have a slight edge, overall the 260 is a arguably a bit faster but for the most part is about the same as a 4870/5770, and respectivly slower then the 4980/5830 etc... so what is your point?? you talk about the gtx 260 and then end with saying get the gtx 460 bc...... it is a good investment for two years??? cmon thats crap use some evidence or fact to back up your reply. Yeah I agree the 460 would be a good buy, but simply saying it is a good investment is garbage your comments are not needed here and you should seriously consider joining up with the ign or best buy forums (if they exist) so your comments will be more in line with the morons that frequent those boards.

 

[jjb8675309]

Not really an important spec..
All the modern cards tend to have 128bit, especially AMD

that is not correct at all, most modern cards run at 256 bits or more with the exception of the 57XX series, 56XX 55XX and lower but the 58XX series, 6 series and the nvidia 4 and 5 series (with the exception of the gtx 460 768mb which used a 192 bit interface) all use 256 bit interface or greater and the higher end 4 and 5 series nvidia cards use a 320 bit interface I believe. Basically anything that is current generation and mainstream or a cusp above is 256 bit or greater and gddr5, but those specs alone will not tell the whole story of performance.

in the end if the op can get back to us with what specific cards they are comparing we can give them a straight answer...

 

[jjb8675309]

yeah I mean basically if you looked at any benchmark for thirty seconds you can quickly determine where performance lies on a series of cards without ever peaking at specs so who really cares, it IS however more important to know approximatley how many minimum, max and avg fps you will get on a given system, game,res,and details... If a card can achieve desired play and you can compare that performance to other cards in its range then what else do you need to help you decide except for reputation of brands and hands on demo. First you have to have a purpose like say play game X at A settings etc, then you look at a benchmark and see what card achieves that level or better performance and go with it.


specs do matter in some regard but...
everything is relative in the end sorry to burst anyone's bubble that is why I like those comparative percentage charts that one of those major forum sites uses...

 

[jjb8675309]

Lol this is personally my favorite qoute and this is what you get when you spend a day off from work mulling around on here look just about 4-5 post above ^^

"if i would be you i would go with gtx 460,it is good investment for two years." -j'91 ah ha ha!