what's diff between new ATI 4750 and 4770 and when it will be avail?

[mikek753]

Hi all,

So far I know those 4750 and 4770 will be based on new 40nm die.
The 4750 is based on 4830, but with faster GDDR5.
Then what would be 4770?
And when those will be avail?

 

[SunnyD]

The 4770 will have GDDR5 while the 4750 will use DDR3 (GDDR3?) memory, same type of different that the 4870 and 4850 enjoy. Neither are "based on" the 4830 - they both use 128-bit buses instead of 256-bit.

 

[KikassAssassin]

No cards based on the RV740 GPU have been officially announced, so we don't know yet. The name "4750" was brought up by rumor sites as a likely possible name for the card, it's not an official name given by ATi. Also, the only version of the card that's been spotted has been the GDDR5 version. For all we know, there might not even be a GDDR3 version. But again, we won't know for sure until the card(s) come out, which rumor has it will be in May.

 

[Flipped Gazelle]

Originally posted by: KikassAssassin
No cards based on the RV740 GPU have been officially announced, so we don't know yet. The name "4750" was brought up by rumor sites as a likely possible name for the card, it's not an official name given by ATi. Also, the only version of the card that's been spotted has been the GDDR5 version. For all we know, there might not even be a GDDR3 version. But again, we won't know for sure until the card(s) come out, which rumor has it will be in May.

It's been pretty well confirmed that the name 4750 will be used, and in fact one European e-tailer briefly had it listed.

Latest rumor has the new cards launching in April.

 

[bunnyfubbles]

Originally posted by: SunnyD
The 4770 will have GDDR5 while the 4750 will use DDR3 (GDDR3?) memory, same type of different that the 4870 and 4850 enjoy. Neither are "based on" the 4830 - they both use 128-bit buses instead of 256-bit.

I don't think anything is official yet, but it would make sense for the memory configs to be that way. Thus far all the xx70 cards have generally been the ones with the faster memory, dating back to the 3870 (GDDR4) and 3850 (GDDR3). However the 4600 line doesn't work this way so who knows what will happen. I wouldn't be surprised if it was GDDR5 only or even GDDR3 only.

And you're right, it isn't based on the 4830, but I can see where the OP got confused. The 4830 is based on a cut down RV770 (4x160=640 as opposed to the standard 5x160=800) while the 47xxs will be based on the RV740 (5x128=640) so same number of shaders as the 4830, just a different (and apparently more efficient) way of getting there.

 

[hans007]

Originally posted by: bunnyfubbles

Originally posted by: SunnyD
The 4770 will have GDDR5 while the 4750 will use DDR3 (GDDR3?) memory, same type of different that the 4870 and 4850 enjoy. Neither are "based on" the 4830 - they both use 128-bit buses instead of 256-bit.

I don't think anything is official yet, but it would make sense for the memory configs to be that way. Thus far all the xx70 cards have generally been the ones with the faster memory, dating back to the 3870 (GDDR4) and 3850 (GDDR3). However the 4600 line doesn't work this way so who knows what will happen. I wouldn't be surprised if it was GDDR5 only or even GDDR3 only.

And you're right, it isn't based on the 4830, but I can see where the OP got confused. The 4830 is based on a cut down RV770 (4x160=640 as opposed to the standard 5x160=800) while the 47xxs will be based on the RV740 (5x128=640) so same number of shaders as the 4830, just a different (and apparently more efficient) way of getting there.

uh the 4600 line does work that way.

4670 has 2000mhz gddr3 and the 4650 has 1ghz ddr2

 

[Denithor]

Eww... 128-bit memory interface? That's going to severely limit bandwidth, especially with GDDR3. Meaning these cards probably won't perform all that well at high resolution and/or with heavy AA/AF enabled.

Comparing current GDDR3/GDDR5 cards to that:
4850: (256/8)*2000 = 64.0GB/s
4870: (256/8)*3600 = 115.2GB/s
4750: (128/8)*2000 = 32.0GB/s
4770: (128/8)*3600 = 57.6GB/s

I mean, the 4750, if these comments prove to be accurate, will only feature about as much memory bandwidth as the current 4670. On the 4670 that's ok as the core isn't powerful enough for the latest games at 19x12 but to limit a 40nm RV770 core with that lousy bandwidth is just criminal (or should be).

Edit:

 

[mikek753]

thanks everyone for the reply.

Looks like 4770 will not be as good as 4850, but costs about the same $120.

I'm looking for performance of 4850, but with less power consumption as it has to be 40nm vs 55nm. And with UVD2 (.264 and VC1) cpu offload.

So tests will tell about how behind those 4750 & 4770 from 4850.
Also I expect 4750 be faster then 4830 - will it not?

 

[hans007]

Originally posted by: mikek753
thanks everyone for the reply.

Looks like 4770 will not be as good as 4850, but costs about the same $120.

I'm looking for performance of 4850, but with less power consumption as it has to be 40nm vs 55nm. And with UVD2 (.264 and VC1) cpu offload.

So tests will tell about how behind those 4750 & 4770 from 4850.
Also I expect 4750 be faster then 4830 - will it not?

well given that the 4770 will have about the same bandwidth as a 4850 / 4830 yet have the same amount of shaders running at slightly higher clocks than a 4830, its probably going to be right in between those 2 cards.


I would figure it wouldnt be a huge dropoff either.

the 4750 is going to probably be some cheap $60-70 card, so if it has say 1800mhz gddr3, even though that might be a bottleneck for the number of shaders i hardly think it would be so horrible a card.


my hope really is that they take the 4670 and shrink it to 40nm and sell it as some sort of entry level $40 card... like say the "4400 series" . this is all speculation by me.


but a say radeon 4670 shrunk to 40nm, with even a 64bit GDDR5 memory path, would probably still be pretty fast for $40.