ASUS EAH4770 review
Author: Luka Rakamaric
Date: 13 Oct 2009

Here we go again with the naming inconsistencies. Up until now, we had a clear rule, the bigger the number, the faster the card. Now, we have an ATI Radeon 4770, a number clearly smaller than 4830, yet we get a faster card, which can knock on the doors of 4850. ATI claims that the performance is not only indicated by the whole four digits, but the last two. The first two digits only represent the series, but in fact we never before had a situation where the fastest card of the lower series is faster than the slowest card of the higher one. All in all, ATI could have just as well named this card 4840 and nobody would complain. Instead, they went for the more complicated nomenclature that does follow a certain logic, but that will surely be lost on some people.

Even though it has the same number of shaders as the 4830, it uses a different core, which is manufactured in a 40nm production process. Its name is RV740, and it is clocked much higher because of that. While the 4830 had to do with a 575 MHz memory clock, probably to make use of the chips unsuited for 4850 and 4870, the 4770 has a clock of 750 MHz. The reference design uses a twin heatpipe dual slot cooler similar to the one found on the 4870, so the card should be quieter than the reference 4850 with its single slot version. However, as we have seen, you can rarely buy a 4850 without a dual slot cooler, as most manufacturers put a third party model on their cards. ASUS 4770 also comes with a third party cooler, which doesn’t look as impressive as the reference version, but with the 40nm production process it doesn’t have much heat to dissipate, so ASUS probably went for the cheaper solution. Most of its power however comes from the use of GDDR5 memory, which compensates for the cheaper 128 bit memory bus used with the 4700 series. It is cheaper to use the more expensive GDDR5 memory, but save with PCB design, then to use a complicated multilayer PCB with the cheaper GDDR3 memory. The end result is the same, as it is the memory bandwidth that counts, and 4770 has 51.2GB/s. So, you get a card that is very similar to the 4850, but with a lower production cost. Right now, you can get both 4850 and 4770 for about the same price of €/$100, but as more time passes with 4770 on the market it should go for less, making it much more attractive.

The rest of the facts for the GPU are that it has 32 texture memory units and 16 render outputs (ROPs). That is of course less than 4850 which has 40 TMUs and 16 ROPs, but what the 4770 lack physically it makes up in core clock, which is 750 MHZ compared to the only 625 of 4850.

With a 40 nm production process, ATI was on the verge of not including the 6 pin power connector on the card, but for overclocking purposes their decision to include it is welcome.

A picture of card with the box: