Northern Islands (GPU family)

Northern Islands Family

Codename(s)	Northern Islands Caicos Turks Barts Cayman Antilles
Created in year	2010
Entry-level cards	6450, 6570
Mid-range cards	6670, 6750, 6770, 6790
High-end cards	6850, 6870
Enthusiast cards	6950, 6970, 6990
Direct3D support	Direct3D 11 Shader Model 5.0
OpenCL support	1.1
OpenGL support	4.1
Predecessor	Evergreen family
Successor	Southern Islands family

The Northern Islands series is a family of GPUs developed by Advanced Micro Devices (AMD) for its Radeon line, based on the 40 nm process.

Starting with this family, the former ATI brand was officially discontinued in favor of making a correlation between the graphics products and the AMD branding for computing platforms (the CPUs and chipsets). Therefore, the AMD brand was used as the replacement. The logo for graphics products and technologies also received a minor makeover (using design elements of the 2010 AMD VISION logo).

Release

The original design was for 32 nm, but TSMC cancelled its 32 nm process in favor of 28 nm development. AMD was forced to adapt its designs as second generation 40 nm products. Even before canceling 32 nm process, TSMC priced their 32 nm process higher than 40 nm.^{[citation needed]} AMD calculated that for mid-range chips, the new VLIW4 architecture (at 32 nm), would not be as cost effective as an updated VLIW5 on 40 nm.^{[citation needed]}

Due to a major delay caused by the 32 nm cancellation, the top parts, Cayman and Antilles (dual Cayman), were delayed causing the mid-range part (Barts) of the series, as AMD moved the smaller chips (Barts, Turks, and Caicos) to 40 nm early, to be launched first.^[1] Also, AMD added stereoscopic 3D support to this Radeon lineup along with HDMI 1.4a and DisplayPort 1.2.

Products

Radeon HD 6400

Codenamed Caicos, this entry-level GPU was released along with Turks on February 7, 2011. The sole Caicos product is the Radeon HD 6450, meant to replace the HD 5450. Compared to the 5450, it has double the stream processors, GDDR5 support, along with new Northern Island technologies.

Radeon HD 6600/6500

Codenamed Turks, these entry-level GPUs were released on February 7, 2011. The Turks family includes Turks PRO and Turks XT which are marketed as HD 6570 and HD 6670 respectively. They were originally released to OEMs only, but later released to retail.

The Radeon HD 6570 and 6670 are minor upgrades of their Evergreen counterparts, the HD 5570 and 5670. Turks GPUs contain 80 more stream processors and 4 more texture units. They have also been upgraded to support the new technologies found in the Northern Islands GPUs such as HDMI 1.4a, UVD3, and stereoscopic 3D.

Radeon HD 6700

Codenamed Barts LE, the mid-range GPU Radeon HD 6790 was released on April 5, 2011. There is one retail product available, the Radeon HD 6790. Barts uses shaders of the same 5-way VLIW architecture as HD 5000 series.

• HD 6790 has 800 stream processors at 840MHz, a 256-bit memory interface and 1 GB GDDR5 DRAM at 1GHz with maximum power draw of 150W. Performance is superior to the NVIDIA GTX 550 Ti and Radeon HD 5770, less powerful than the Radeon HD 6850 and close to the GTX 460 768MB and Radeon HD 5830.

AMD has confirmed that the HD 6700 cards use the Juniper XT and Juniper Pro cores (same cores as the HD 5700 series). Thus 6770 and 6750 cards are essentially rebranded 5770 and 5750 respectively, with label being the main difference

• The HD 6750 comes in at 720 stream processors clocked at 700MHz. The memory is packed in the same amount but clocked a tad slower at 1.15GHz (4.6GHz effective), resulting in 73.66GB/s bandwidth, which lines up perfectly with the outgoing HD 5750.

• In previous HD 6000-series cards, AMD’s Universal Video Decoder was upgraded to version 3.0 which supported BluRay 3D codecs, hardware decoding for DivX / xVid and a list of other improvements. The HD 6700-series however carries over Juniper’s UVD 2.0 so none of these new formats are processed through the GPU.

• According to AMD, these cards have been upgraded to support HDMI 1.4a but without the 3D features brought forward by UVD 3.0.

Radeon HD 6800

Codenamed Barts, the performance (high-end) GPU Radeon HD 6800 series was released on October 22, 2010. Products include Radeon HD 6850 and Radeon HD 6870. Barts uses shaders of the same 5-way VLIW architecture as HD 5000 series.^[2]

• HD 6850 has 960 stream processors at 775MHz, a 256-bit memory interface and 1 GB GDDR5 DRAM at 1GHz with maximum power draw of 127 W. Compared to competitors of the GTX 460 series, performance falls in line with the 1 GB cards of the NVIDIA GTX 460 series and superior to the 768MB GeForce GTX 460. Compared to predecessor graphics of the Radeon 5800 series, the 6850 is significantly faster than the Radeon HD 5830 and close to the performance of the Radeon HD 5850. A single 6-pin PCIe power connector requirement makes it suitable for most power supplies.

• HD 6870 has 1120 stream processors at 900MHz, a 256-bit memory interface and 1 GB GDDR5 DRAM at 1.05GHz (4.2GHz effective) with a maximum power draw of 151 W. Performance is superior to the GeForce GTX 460, comparable to the GeForce GTX 560, and less than the GeForce GTX 560 Ti. Compared to predecessor graphics cards of the Radeon 5800 series, the 6870 is faster than the HD 5850 and close to the performance of the Radeon HD 5870.^[3]

Radeon HD 6900

This family includes three different high-end products.

Codenamed Cayman, the enthusiast GPU Radeon HD 6900 series was expected to be released on November 12, 2010. These release dates were pushed further back and Cayman was released on December 15, 2010. Products include Radeon HD 6950 and Radeon HD 6970. Cayman is based on new 4-way VLIW architecture, which was chosen over AMD's older VLIW5 in order to reduce complexity in the design of AMD's stream processors. Studies showed that few applications fully leveraged the extra stage in a VLIW5 SP. Reducing the stream processors to VLIW4 allows AMD to save on transistors for each individual SP and add more overall in the future.^[4]

• In games, the performance of HD 6970 is comparable to the NVIDIA GeForce GTX 570 and GTX 480. The Radeon HD 6950 is slightly slower than the 6970, comparable to slightly faster than the GTX 560 Ti and faster than the HD 5870. The HD 6950 was further discovered to be nearly identical to the 6970 in core design, though the 6950 has lower rated GDDR5 memory. Other than that, the two only differed in BIOS flashed software. As such, a BIOS flash would essentially upgrade the 6950 to a 6970. This was later addressed by AMD and its partners by laser cutting the extra cores (rather than simply disabling them in BIOS), and/or using non-reference card designs that would not work with a 6970 BIOS. Some 6950s can still be "unlocked", but it is much more difficult, requiring careful card selection and custom BIOS.

• Codenamed Antilles, the Enthusiast dual-GPU (dual-6970) Radeon HD 6990 was launched on March 9, 2011. It features an 830 MHz reference engine clock speed, 3072 stream processors, 5.1 TFLOPS computing performance, 192 texture units, 4 GB of GDDR5 frame buffer (DRAM), and 375 W maximum board power.^[5]

• The AMD Radeon HD 6990 (As with some other 6000 Series AMD Cards) comes with a dual BIOS switch. This enables what some claim to be a hidden 'AMD Uber Mode', however it is used most commonly as a backup when flashing the BIOS. (The same method used to flash the HD 6950 to appear as a HD 6970)^[6]

ASIC table

Main article: Comparison of AMD graphics processing units

Northern Islands (HD 6xxx) series overview

• All models manufactured in a 40 nm fabrication process.
• All models support DirectX 11, OpenGL 4.2 and OpenCL 1.1

Model	Year	Code name	Transistors (Million)	Die Size (mm2)	Bus interface	Memory (MiB)	Clock rate		Config core1	Fillrate		Memory			GFLOPS	TDP3 (W)		Double-precision FP	Features / Notes	Release Price (USD)
							Core (MHz)	Memory (MHz)		Pixel (GP/s)	Texture (GT/s)	Bandwidth (GB/s)	Bus type2	Bus width (bit)		Idle	Max.
Radeon HD 6450[7]	Feb 7, 2011 (OEM) Apr 7, 2011 (retail)	Caicos	370	67	PCIe 2.1 x16	512 1024	625-750	533-800 800-900	160:8:4	2.5-3	5-6	8.5-12.8 25.6-28.8	DDR3 GDDR5	64	200-240	9	18 27	No		$55 (GDDR5)
Radeon HD 6570[8]	Feb 7, 2011 (OEM) Apr 19, 2011 (retail)	Turks	716	118	PCIe 2.1 x16	1024 2048	650	900 1000	480:24:8	5.2	15.6	28.8 64	DDR3 GDDR5	128	624	10 11	44 60	No		$79 (GDDR5)
Radeon HD 6670[9]						512 1024	800	1000		6.4	19.2	64	GDDR5		768	12	66			$99
Radeon HD 6750[10]	Jan 21, 2011 (OEM) Apr 28, 2011 (retail)	Juniper PRO	1040	170	PCIe 2.1 x16	512 1024	700	1150	720:36:16	11.2	25.2	73.6	GDDR5	128	1008	16	86	No
Radeon HD 6770[11]		Juniper XT					850	1200	800:40:16	13.6	34	76.8			1360	18	108
Radeon HD 6790	Apr 4, 2011	Barts LE	1700	255	PCIe 2.1 x16	1024	840	1050	800:40:16	13.4	33.6	134.4	GDDR5	256	1344	19	150	No	HD3D UVD3 HDMI 1.4a	$149
Radeon HD 6850[12]	Oct 22, 2010	Barts Pro					775	1000	960:48:32	24.8	37.2	128			1488		127[13]		HD3D UVD3 HDMI 1.4a DP 1.2[N 1][14]	$179
Radeon HD 6870[15]		Barts XT					900	1050	1120:56:32	28.8	50.4	134.4			2016		151[13]			$239
Radeon HD 6950[16]	Dec 15, 2010	Cayman Pro	2640[17]	389[17]	PCIe 2.1 x16	1024 2048	800	1250	1408:88:32	25.6	70.4	160	GDDR5	256	2253	20[18]	200[18]	563	HD3D UVD3 HDMI 1.4a DP 1.2 Dual BIOS option	$259 $299
Radeon HD 6970[19]		Cayman XT				2048	880	1375	1536:96:32	28.2	84.5	176			2703		250[18]	675		$369
Radeon HD 6990	Mar 8, 2011[20]	Antilles	2640 ×2	389 ×2	PCIe 2.1 x16	2048 ×2	830	1250	1536:96:32 ×2	2× 26.5	2× 79.6	2× 160	GDDR5	2× 256	5099	37	375	1276.88	HD3D UVD3 HDMI 1.4a DP 1.2 Dual BIOS option	$699

• ¹ Unified Shaders (Vertex shader/Geometry shader/Pixel shader) : Texture mapping unit : Render Output unit
• ² The effective data transfer rate of GDDR5 is quadruple its nominal clock, instead of double as with other DDR memory.
• ³ The TDP is reference design TDP values from AMD. Different non-reference board designs from vendors may lead to slight variations in actual TDP.

1. ^ DisplayPort rev.1.2 (DP1.2) provides 21.6Gbps / 17.28Gbps dedicated video bandwidth (VBW) (2x DP1.1 bandwidth -> 10.8Gbps / 8.64Gbps VBW; or 2x VBW as a DL-DVI) that supports higher resolutions up to 4096x2160@50Hz or few lower resolutions with 30-bit color depth, 48Mbps for bitstreaming audio enables unrestricted LPCM (e.g. 8ch LPCM 192khz/24b) along with support for Dolby and DTS lossless audio formats, and 3D stereoscopy (AMD's HD3D). Also, DP1.2 supports Multi-Stream Transport (MST) which allows transmitting several video streams as interleaved packets several through single port.

See also

• Radeon
• Evergreen (GPU family)
• Southern Islands (GPU family)

References

1. ^ SemiAccurate: What happened with AMD's Northern Islands? by Charlie Demerjian, 20th Dec 2010
2. ^ AnandTech: ATI’s Radeon HD 6870 & 6850: Renewing Competition in the Mid-Range Market by Ryan Smith, 21st Oct 2010
3. ^ [1] by Anonymous, 15th March 2011
4. ^ AnandTech: ATI's Radeon HD 6970 & 6950: Paving The Future For AMD by Ryan Smith, 15th Dec 2010
5. ^ [2] by Chris Angelini, 8th Mar 2011
6. ^ [3] by Anonymous, 15th Mars 2011
7. ^ HD 6450 Graphics (For OEM Only)
8. ^ HD 6570 Graphics (For OEM Only)
9. ^ HD 6670 Graphics (For OEM Only)
10. ^ HD 6750 Graphics (For OEM Only)
11. ^ HD 6770 Graphics (For OEM Only)
12. ^ AMD Radeon™ HD 6850 graphics, Advanced Micro Devices, Inc., http://www.amd.com/us/products/desktop/graphics/amd-radeon-hd-6000/hd-6850/Pages/amd-radeon-hd-6850-overview.aspx#2, retrieved 4 October 2010 
13. ^ ^{a b} Smith, Ryan (21 October 2010), AMD’s Radeon HD 6870 & 6850: Renewing Competition in the Mid-Range Market, AnandTech, p. 1, http://www.anandtech.com/show/3987/amds-radeon-6870-6850-renewing-competition-in-the-midrange-market/1 
14. ^ Smith, Ryan (21 October 2010), "Seeing the Future: DisplayPort 1.2", AMD’s Radeon HD 6870 & 6850: Renewing Competition in the Mid-Range Market, AnandTech, p. 3, http://www.anandtech.com/show/3987/amds-radeon-6870-6850-renewing-competition-in-the-midrange-market/3 
15. ^ AMD Radeon™ HD 6870 graphics, Advanced Micro Devices, Inc., http://www.amd.com/us/products/desktop/graphics/amd-radeon-hd-6000/hd-6870/Pages/amd-radeon-hd-6870-overview.aspx#2, retrieved 4 October 2010 
16. ^ AMD Radeon HD 6950 Graphics
17. ^ ^{a b} AMD's Radeon HD 6970 & Radeon HD 6950: Paving The Future For AMD
18. ^ ^{a b c} AMD's Radeon HD 6970 & Radeon HD 6950: Paving The Future For AMD
19. ^ AMD Radeon HD 6970 Graphics
20. ^ AMD Radeon HD 6990 Launch on 8th March, VR-Zone, http://vr-zone.com/articles/amd-radeon-hd-6990-launch-on-8th-march/11397.html, retrieved 28 February 2011 

External links

• Ryan Smith (December 15, 2010). "AMD's Radeon HD 6970 & Radeon HD 6950: Paving The Future For AMD". anandtech.com. http://www.anandtech.com/show/4061/amds-radeon-hd-6970-radeon-hd-6950. Retrieved January 10, 2011. 
• David Kanter (December 14, 2010). "AMD's Cayman GPU Architecture". realworldtech.com. http://www.realworldtech.com/page.cfm?ArticleID=RWT121410213827. Retrieved January 10, 2011. 
• AMD Radeon HD 6000 series