640 Shader, 40nm and GDDR5 for less than 100 Euros
Review: Ati RadeonHD 4770 vs. HD 4850 & Geforce 9800 GT
The Radeon HD 4770 is the first desktop graphics card with an RV740 GPU in 40 nanometer structure. Ati's new card competes with the Radeon HD 4850, Geforce 9800 GT and Co.
With the Radeon HD 4770, the first graphics card with "40 nanometer GPU” AMD wants to enter the crowded sector of sub 100 Euros graphics cards. We tested with up-to-date drivers and with common games like Call of Duty: World at War (dt.), Race Driver Grid or Fallout 3 if the card can succeed in its field of operation.
Radeon HD 4770 Launch-Review [Source: view picture gallery]
Radeon HD 4770 Launch-Review (21) [Source: view picture gallery]
Due to the 40 nanometer technology and the slim 128 Bit memory interface the production costs and thus the prices for the customers are supposed to be kept low. The GDDR5 is expensive, but it runs much better than according GDDR3 chips. The number of operating units and the clock speeds indicate a performance level between HD 4830 and HD 4850 - all in all a quite interesting card that is introduced today. AMD expects a price between 90 and 100 Euros for the market introduction.
Ati Radeon HD 4770: Technical specifications We want to keep it short and summarized the most important specifications in the table below. The RV740 chip is divided into 8 SIMD units with 16 optimized 5-way ALUs each. Each of the SIMDs has access to a Quad TMU so that all in all 32 texture values can be handled per clock.
Tech-Specs
AMD Radeon
Nvidia Geforce
Graphics card
HD 3870
HD 4670
HD 4770
HD 4830
HD 4850
9600 GT
9800 GT
9800 GTX
Chip
RV670
RV730
RV740
RV770
RV770
G94 (b)
G92(b)
G92(b)
Structure (Nanometer)
55
55
40
55
55
65 / 55
65 / 55
65 / 55
Transistors (Mio.)
666
514
826
956
965
505
754
754
Chip frequency (MHz)
775
750
750
575
625
650
600
675
Shader ALUs frequency (MHz)
775
750
750
575
625
1,625
1,512
1,688
Memory frequency (MHz)
1,125
1,000
800
900
1,000
900
900
1,100
VRAM transactions per second (Mio)
2,500
2,000
3,600
1,800
2,000
1,800
1,800
2,200
Shader version
4.1
4.1
4.1
4.1
4.1
4.0
4.0
4.0
Shader ALUs
320
320
640
640
800
64
112
128
Double-Precision (FP64)
Ja
No
Yes
Yes
Yes
No
No
No
Raster operators (ROPs)
16
8
16
16
16
16
16
16
Texture units (INT/TMUs)
16/16
16/32
32/32
32/32
32/40
32/32
56/56
64/64
FP16 textures
Single-Cycle
Dual-Cycle
Dual-Cycle
Dual-Cycle
Dual-Cycle
Dual-Cycle
Dual-Cycle
Dual-Cycle
Default memory amount (MiB)
512
512
512
512
512
512
512
512
Memory bus/transmission (Bit)
256, DDR
128, DDR
128, QDR*
256, DDR
256, DDR
256, DDR
256, DDR
256, DDR
Memory type
GDDR4
GDDR3
GDDR5
GDDR3
GDDR3
GDDR3
GDDR3
GDDR3
Calculation power (MADD, GFLOPS)
496
480
960
736
1000
208
338
432
Pixel fillrate (MTex/s)
12,400
6,000
12,000
9,200
10,000
10,400
9,600
10,800
Texture fillrate (filtered MTex/s)
12,400
24,000
24,000
18,400
25,000
20,800
33,600
43,200
Z fillrate (MZix/s)
24,800
12,000
24,000
18,400
20,000
83,200
76,900
86,400
Memory bandwidth (MByte/s)
72,000
32,000
51,200
57,600
64,000
57,600
57,600
70,400
PCI-E power connector (6-/8-Pin)
1x/0x
0x/0x
1x/0x
1x/0x
1x/0x
1x/0x
1x/0x
2x/0x
TDP/Max. Board-Power (Watt)
106
59
80
n.a.
110
95
110
156
Length PCB (mm, ca.)
229
168
208
229
229
228
228
267
The high data transfer rate of the GDDR5 - on our test sample there are 40 modules from Qimonda - compensates the slim, size efficient interface almost completely; thus the HD 4770 has enough bandwidth per Pixel/Texel (more is better of course). In contrast to the RV730 GPU on the HD 4670 the RV740 also supports the so called "Doubles”, FP64 or Double Precision, which are primarily used in extremely exact scientific calculations.
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