CPU and GPU upgrade (AMD and Radeon)

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soumo27

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^^a 6670/5670 can also make things playable at that resolution with high settings......but not for a long time, though.. :D
 

Cilus

laborare est orare
According to wikipedia, the HD7xxx will utilise smaller sized die, which will allow for more stream processors... Can you please explain what stream processors are? And is more stream processors better? Sorry, please bear with my newbie questions..

Stream processors or unified shaders are a standard starting from nVidia 8000 series and AMD 3000 series which actually embedded the Vertex processing unit(Vertex Shader unit), Pixel processing Unit (Pixel Shader Unit) and Reverser station ( to store the fetched instructions) into a single unit called Stream processors.
in case of nvidia, each of the stream processors is capable of processing a single thread and utilize the TLP or thread level parallelism whereas in case of AMD/ATI a group of 5 stream processors (in case of ATI 4000, 5000 and 6800 series) or 4 stream processors (in case of HD 6900 series) are grouped together to process one thread. For example HD 5870 is having 1600 stream processors means it actually has (1600/5) =320 independent units and each of them can process a different thread. Unlike nvidia, AMD takes the benefit of Instruction level parallelism or ILP and can process multiple instructions simultaneously inside one thread.

And yes, more number of stream processor means more performance.
 
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sukesh1090

Adam young
@skud,
yes sorry it is 6770.and i think 6670 will also does the job at that resolution at least for two years.
@cilus,
In the previous post you told this,
A HD 6870 with its 1140 stream processors offers performance better than a HD 5850 with 1440 stream processor
so how can is it possible?i don't know much about this,so just an inquiry.
 
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ico

Super Moderator
Staff member
Just explaining what Cilus said through a diagram:
*images.anandtech.com/reviews/video/ATI/4800/ilp.png

This actually results in AMD having a smaller die size. Smaller die size = more chips per wafer. More chips per wafer = chances of a better yield and more profit.

You have to see, HD 6970 is only 389 sq. mm and the competing GTX 570 is 520 sq. mm.

From HD 6900 series, AMD uses VLIW4 which is 4 instructions wide instead of VLIW5 because AMD felt that VLIW5 was being underutilized and it was better to have one unit cut for better transistor efficiency. They also wanted to add more tweaks/features to their HD 6900 cards but were not able to do so because of TSMC's delayed 28nm fabrication.

I'll also give you a small example between GTX 460 and HD 6850/6870 (VLIW5).

GTX 460 has 336 stream processors according to nVidia. HD 6850 and HD 6870 have 960 and 1120 respectively which work in groups of 5. If you want you could also say, 192 and 224 stream processors. Both HD 6850 and HD 6870 still manage to outperform GTX 460.
 

Souro_Ray

In the zone
@Cilus and ico

Thanks guys.. That kind of clears things up a bit in my head...

@ico,

Thanks for fixing my posting problem, bro...
 

Cilus

laborare est orare
@skud,
yes sorry it is 6770.and i think 6670 will also does the job at that resolution at least for two years.
@cilus,
In the previous post you told this,

so how can is it possible?i don't know much about this,so just an inquiry.

AMD BART architecture uses more efficient Stream processors than their old 5000 series. So each of the stream processors are more capable than the 5000 series stream processors and can perform more tasks in a given time frame. As a result even with less number of stream processors, a HD 6870 can beat a HD 5850 because of its advanced design.

For example the 1st generation 3.2 GHz Pentium D dual core processors can't beat the 1.86 GHz Core2Duo processors as Core2Duo has far better architecture than the Pentium D processors.
 

Souro_Ray

In the zone
yeah, that makes sense... A 2ghz dual core AMD outperforms a 3.2ghz single core Intel... Experienced it... You read about comparisons.. but when you see for yourself a certain advertised new product actually beating a slightly older product, it feels weird..
 
OP
M

Mario

Ambassador of Buzz
Mario, dont put misleading information withut understanding what you are writing. HD 6770 is just a re-branded HD 5770, based on the old juniper architecture and has 40 Texture unit and 16 ROPS.

HD 6790, on the other hand, based on the updated BART architecture which is far optimized version of the 5000 series architecture. their stream processors are far more efficient then 5000 series. A HD 6870 with its 1140 stream processors offers performance better than a HD 5850 with 1440 stream processor. Also the tessellation units of BART provide better tessellation performance.
Now HD 6790 is also having same number of stream processors, ROPs and Texturing units as HD 6770 but it is based on BART architecture and more efficient + HD 6790 has 256 bit memory bus, providing double the bandwidth of HD 6770. So its better than HD 6770 and HD 6770 does not provide better AA and AF performance. Check any review.

Cilus, I know Barts > Juniper! I also know 6770-5770=label change only!! But,

if you consider only the 6790, despite being Barts LE, its a severly crippled Barts...which brings it down to almost the same spec as the 6770 Juniper XT on paper at least!! Which is the point I was trying to make! Dont have time to waste on "putting misleading information withut understanding what you are writing"! :)

The only mistake I made was I read too much on these charts !! You got to give it, in theory, the 6770 looks > than the 6790...and the crippled Barts architecture does not help!!

Having said that, I checked the Guru3D VGA charts and mostly I see the 6790 edging out the 6770/5770 by a mere 3~5 fps on average! No doubt, this is the double mem bandwidth in play here!!

Don't get me wrong! I am not saying Barts architecture makes no difference as compared to Juniper! But the impact of the new architecture is not so much in the case of the 6790 as in other 6xxx cases!!

despite featuring a larger and more capable GPU, the Radeon HD 6790's specifications are strikingly similar to those of the Radeon HD 5770, which AMD now sells in pre-built PCs as the Radeon HD 6770.
From a bird's eye view, the 6790's only notable holdover from the 6800 series is the 256-bit memory interface, which the 5770's Juniper GPU is physically incapable of matching. AMD couldn't put Juniper on stilts, so the quick-and-easy alternative was to pay Barts a visit and shatter its tibias with a baseball bat. The fractures incapacitated four of Barts' SIMD arrays, leaving it with 800 ALUs and the ability to filter only 40 textures per clock. This latest example of GPU hobbling also destroyed half of Barts' rasterization capabilities, limiting it to pushing only 16 pixels/clock. As a result, the 6790 and the 5770 have identical ALU counts, and they can filter the same number of pixels and textures per clock.

The Radeon HD 6790 has slightly weaker number-crunching capabilities than the 5770

Source for above


Barts uses shaders of the same 5-way VLIW architecture as HD 5000series.
So, lesser SPs will pull down the 6790 somewhat in direct comparison to the 5770/6770!

Source for above


AMD bases this on the fact that the 5770/6770 and the 6790 are so close in terms of specs; they want to frame the 6790 in terms of the 5770/6770, rather than in terms of the 6800 series.

Seems AMS themselves want it that way!!

Source for above


I guess I was only trying to decide which ones the best GPU for my friends config between 6770/6790! I still think its 6770 coz in my opinion a 150W TDP for 5 extra fps aint good enough!

Anyway, I might still be wrong, I might still be "putting misleading information withut understanding what you are writing" ;) - so plz do correct me if it is so...Me humbly accept me total noob!! :p
 

ico

Super Moderator
Staff member
tbf, I'd rather get HD 6770/5770 than HD 6790. HD 6790 is made from chips which were unfit to be HD 6870. Moving above HD 6770, I'd get GTX 460 or preferably HD 6850. GTX 550 Ti is a failure.

HD 6790 gets the performance right, but not the power consumption. GTX 550 Ti gets both the performance and power consumption wrong.
 

Souro_Ray

In the zone
I agree... I do not speak from experience, but checking out too many performance comparison charts... But i still agree with ico about the 5770/6770 and the GTX 460...
 
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Souro_Ray

In the zone
With hadda haddi competition, everyone makes mistakes... Nvidia has some crap cards, so does Radeon... I remember reading in PC Gamer about when the GTX280 came out: people were blown away by its performance and said that this card left Radeon in the dust.. A couple of months later, Radeon came out with the HD57xx and HD58xx cards and kicked ass and took names! This kind of competition is nice...
 
OP
M

Mario

Ambassador of Buzz
errrr.....what is the purpose of this thread?discussions?
i couldn't get it, thats why

Hehehehe!! just read the first post!! was just deciding gpu/cpu/psu combo for a friend! have already decided...will post back here once bought!!
 

Cilus

laborare est orare
Listen, still my point holds...The choice of Graphics card varies from person to person and MArio, you have proffered HD 6770 over a HD 6790 due to your reasons like lower power consumption and prce. But you have written HD 6770 provides better performance than HD 6790 with AA and AF on which is misleading. And How can I know about your decision taking is decided by Paper and Pen specs?

I was just telling that HD 6790 is more powerful due to its new architecture and 256 bit memory bus...that's all.... I didn't ask you to purchase it...ultimately it is your choice.

And regarding your crippled architecture thing... HD 6790 is launched to compete against the GTS 550 and it has done it well and successfully in a lower price point, not to provide tou unbeatable performance in very lower price. What do you expect...HD 6790 should deliver more performance than GTX 460...then there is HD 6850 already.
 
OP
M

Mario

Ambassador of Buzz
Listen, still my point holds...The choice of Graphics card varies from person to person and MArio, you have proffered HD 6770 over a HD 6790 due to your reasons like lower power consumption and prce. But you have written HD 6770 provides better performance than HD 6790 with AA and AF on which is misleading. And How can I know about your decision taking is decided by Paper and Pen specs?

My decision taking is not decided by Paper specs!! I already said that's where I made the mistake....Made that post after checking the theoretical comparison where surely if u check my link, the 6770 comes on top of the 6790....and then checked the Guru3D VGA charts!! I should have done it the other way round before making that post!!

I was just telling that HD 6790 is more powerful due to its new architecture and 256 bit memory bus...that's all.... I didn't ask you to purchase it...ultimately it is your choice.

No u didnt and I know its my choice ultimately..but we both now this, so why state it so bluntly?? :p

And regarding your crippled architecture thing... HD 6790 is launched to compete against the GTS 550 and it has done it well and successfully in a lower price point, not to provide tou unbeatable performance in very lower price. What do you expect...HD 6790 should deliver more performance than GTX 460...then there is HD 6850 already.

No I dont expect it to!! U have missed my point completely!!

1. First, I was comparing only the 6770 with the 6790!!

2. If u take these 2 gpus only, then I felt that in a scenario where Power consumption is a deciding factor, (I felt) that the 6770 is more bang for buck than the 6790!! coz the 3~5 extra fps 6790 gives is more becoz of its double mem bandwidth than due to its new architecture (coz the new architecture is so severely handicapped here in the case of the 6790)!! Again, dont get me wrong..I am not saying Barts lesser than Juniper!! But that holds only from the 68xx onwards!! Where Barts can show its full power!! For 6790 its only pro is its double mem bndwdth!! Not its new architecture...And if you did check the links I provided in my earlier post, you will see everywhere how close they are in performance! Now if u see perf of other 68xx cards, u will see they are much higher becoz in their case, the new architecture makes lot of difference!! So if someone wants to get Barts, he should start from 6850 onwards!! 6790 not worth it simply for Barts!! 6770 gives almost same perf as 6790 for lesser TDP...thats my prime point here!!

3. Finally, I have already accepted that I had read too much into the theoretical comparison - my mistake - no need to harp on it so much!!
 

Cilus

laborare est orare
Ok buddy, I understood..lets stop it right now. When are you gonna make the purchase? By the way. I was checking that there are some Oced version of HD 6770 have also been released. Check if you can get hands on one of those.
 

Skud

Super Moderator
Staff member
Listen, still my point holds...The choice of Graphics card varies from person to person and MArio, you have proffered HD 6770 over a HD 6790 due to your reasons like lower power consumption and prce. But you have written HD 6770 provides better performance than HD 6790 with AA and AF on which is misleading. And How can I know about your decision taking is decided by Paper and Pen specs?

I was just telling that HD 6790 is more powerful due to its new architecture and 256 bit memory bus...that's all.... I didn't ask you to purchase it...ultimately it is your choice.

And regarding your crippled architecture thing... HD 6790 is launched to compete against the GTS 550 and it has done it well and successfully in a lower price point, not to provide tou unbeatable performance in very lower price. What do you expect...HD 6790 should deliver more performance than GTX 460...then there is HD 6850 already.


The 6790 doesn't compete with 550Ti, it completely decimates it in almost every games. If you are tight on budget, this is a wonderful card for its price point.
 
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