Whats more important - total memory bandwidth or stream processing units?

[TheDarkKnight]

Im debating on whether or not to purchase an NVidia GeForce 550 ti with 98.5 GB/sec of memory bandwidth with its 192-bit memory bus-width which is awesome bandwidth but it only has 192 SP's(Stream Processors).

The AMD 6770 has roughly 25% less total memory bandwidth(according to wikipedia charts) at around 76.8 GB/sec total memory bandwidth using its 128-bit memory bus-width but it has 800 SPs. 4x as much as a GeForce 550 ti.

These cards are basically the same price so they are direct competitors. Which is better to have do you think. The one with more total memory bandwidth or more stream processors?

Edit: Do any video games actually ever use 800 SP's? Is 800 SPs overkill?

 

[dpk33]

I'm really new to this, but - why do all of these technical things matter? Isn't the end performance what really matters?

 

[TheDarkKnight]

I'm really new to this, but - why do all of these technical things matter? Isn't the end performance what really matters?

I find your question somewhat redudant to my own. Thats what I am trying to figure out. Which card will give the best performance and how that card will achieve the best performance. In other words, what is more important to achieve the best performance in video games, total memory bandwidth or SPs? Is 98 GB/sec total memory bandwidth overkill? Is 800 SPs overkill?

I coulda just asked which is the fastest card of the two but I strongly fear there isn't a black and white answer to this question. Probably depends on the video games being played but Im no expert. Therefore, I ask.

Edit: I also consider myself a knowledge whore. I honestly don't just wanna know which card is the best buy for me but I want to understand for myself why its the best card for me.

 

[dpk33]

I find your question somewhat redudant to my own. Thats what I am trying to figure out. Which card will give the best performance and how that card will achieve the best performance. In other words, what is more important to achieve the best performance in video games, total memory bandwidth or SPs? Is 98 GB/sec total memory bandwidth overkill? Is 800 SPs overkill?

I coulda just asked which is the fastest card of the two but I strongly fear there isn't a black and white answer to this question. Probably depends on the video games being played but Im no expert. Therefore, I ask.

From what i've seen, the amount of stream processors aren't everything. Nvidia cards and ATI/AMD cards have a really big difference in stream processors, yet they still perform similarly. It's probably the difference their architecture, but correct me if i'm wrong.

As to which card is better, I'm sure many people would say it depends what you are planning on doing with it. e.g. ATI/AMD cards > Nvidia in bitcoin mining.

 

[Blitz KriegeR]

It's probably the difference their architecture, but correct me if i'm wrong.

As to which card is better, I'm sure many people would say it depends what you are planning on doing with it.

Correct Sir. To put it plainly, AMD uses many less powerful "cores" to make their GPUs, while Nvidia tends to use less more versatile ones. Comparing SPs would only be accurate if you are comparing manufacturers. IE comparing the SP count on an Nvidia card to an AMD one is apples to oranges.

Oh and if you need a GPU in that price range, I'd highly suggest picking up one of these:

http://www.newegg.com/Product/Produc...-14130690-L02A

It will out perform both the 550ti and the 6770 for $95. Be warned it's re-certified, not brand new, but I would not worry.

EDIT: If you can afford it, here is any even better deal: a Full GTX460 brand new for $129 after rebate.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130565

 

[Red Hawk]

What dpk33 and Blitz KriegeR said. Nvidia and AMD's shader architecture is not comparable based solely on the amount of shader processors; AMD uses a lot of small shader processors while Nvidia uses fewer but beefier shader processors.

As for general shading performance vs. memory performance, both are important but I'd put shading first.

 

[Crap Daddy]

Don't compare the shader processors on Nvidia with AMD. Lately Nvidia calls them "CUDA cores". Check for performance reviews in benches and games, that'll give you a more accurate perspective.

 

[Arkadrel]

Im debating on whether or not to purchase an NVidia GeForce 550 ti with 98.5 GB/sec of memory bandwidth with its 192-bit memory bus-width which is awesome bandwidth but it only has 192 SP's(Stream Processors).

The AMD 6770 has roughly 25% less total memory bandwidth(according to wikipedia charts) at around 76.8 GB/sec total memory bandwidth using its 128-bit memory bus-width but it has 800 SPs. 4x as much as a GeForce 550 ti.

These cards are basically the same price so they are direct competitors. Which is better to have do you think. The one with more total memory bandwidth or more stream processors?

Edit: Do any video games actually ever use 800 SP's? Is 800 SPs overkill?

overall (I think):
Nvidia 460 > AMD 6770 > Nvidia 550 ti

It depends on the game, and their pretty close in performance.
You can probably just get whichever is cheaper, and never really notice a differnce.

 

[SlowSpyder]

They GPU cores and SP counts are not directly comparable to one another. AMD and Nvidia use different architectures. Those cards are probably fairly close in performance, which one is cheaper, has a better warranty, does one come with a game that you'd want to plat, etc? Something else worth considering is that the 192 bit Nvidia cards typically have 768MB of memory, the 6770 is a 1GB card. If you are going to try and game at 1080P that may make a difference.

If you were under the impression that those cards are direct competitors because of the SP's vs. memory bandwidth, just as an FYI, that's not the case. It has more to do with the GPU cores, though the memory bandwidth can come in to play in some situations as well.

 

[DominionSeraph]

We have sites like Anandtech running benchmarks for a reason -- you can't tell just by looking at specs.

 

[BrightCandle]

As others have said you can't compare the specs from the two companies.

But the original question of whether bandwidth verses SP is an interesting one. The ideal combination is a balance of both where you have just enough bandwidth to feed the SP. If the SP are sitting waiting for RAM its no good and if they are faster then RAM then they can't do anything until there is space to read and write to it. So just as you can't compare SP counts on the two cards nor can you really compare memory bandwidth - because arguably they are using it in different ways AND it may not balance correctly with the number of SPs and the amount of work they are doing.

The only way to compare graphics cards is with reviews running real games. HardOCP, Tomshardware and Anandtech will all give you good comparisons that will inform your purchasing decision.

 

[BFG10K]

Most mid/high-range cards benefit more from core increases than bandwidth increases. That’s to say they have enough of bandwidth so it’s not the primary bottleneck.

 

[Spikesoldier]

AMD SP's and NV SP's are not an apples to apples comparison. Adding more memory bandwidth doesn't necessarily improve performance either, it will depend on the specific card used.

Look up benchmarks in the games you desire to play, then pick your top performer based on your budget.