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Thursday, April 1, 2010

AMD's 890GX Chipset - Same Graphics, Better South Bridge


AMD's 890GX Chipset - Same Graphics, Better South Bridge

No news isn’t always good news. AMD has been purposefully vague on the graphics specifications of its 8-series chipsets. Today we know why. The AMD 890GX has the exact same graphics horsepower as the 790GX:

AMD 890GXAMD 790GXAMD 785G
CPUAMD Socket-AM3AMD Socket-AM3/AM2+AMD Socket-AM3/AM2+
Manufacturing Process55nm55nm55nm
PCI Express24 PCIe 2.0 lanes22 PCIe 2.0 lanes22 PCIe 2.0 lanes
GraphicsRadeon HD 4290 (DirectX 10.1)Radeon HD 3300 (DirectX 10.0)Radeon HD 4200 (DirectX 10.1)
Core Clock700MHz700MHz500MHz
Shader Processors8 (5-way)8 (5-way)
Full H.264/VC-1/MPEG-2 HW DecodeYes (UVD2)Yes (UVD)Yes (UVD2)
8-channel LPCMNoNoNo
South BridgeSB850SB750SB750
USB14 USB 2.0 ports12 USB 2.0 ports12 USB 2.0 ports
SATA6 SATA 6Gbps ports6 SATA 3Gbps ports6 SATA 3Gbps ports

In fact, it’s virtually the same graphics core as the 790GX and 785G built on the same 55nm process.


AMD 890GX North Bridge (left) vs. AMD 790GX North Bridge (right) - nothing has changed


SidePort memory on a motherboard

For those of you who aren’t familiar with AMD’s integrated graphics, it’s a 40 SP implementation of the RV6xx core running at 700MHz. The chipset supports optional SidePort memory. It’s an optional dedicated frame buffer that provides additional low latency bandwidth to the integrated graphics core. If your application demands more memory, the GPU can still use the CPU’s memory controller and system memory.

There haven’t been any improvements to the audio side of the chipset either. The 890GX still supports 2-channel LPCM or 5.1 Dolby Digital/DTS bitstreaming over HDMI. If you want more, AMD will happily sell you a Radeon HD 5450 to plug in to your new board.

AMD continues to offer full hardware H.264/MPEG-2/VC-1 video decode acceleration. The UVD2 engine responsible for the video acceleration remains unchanged from the 785G and 790GX.


Boards based on the 890GX will be well equipped with video outputs like this ASUS M4A89GTD Pro/USB3

Overall system performance remains unchanged. The 890GX performs no differently than the 790FX/GX chipsets:

AMD 890GXAMD 790GX
x264 HD Encode - Average FPS26.6 fps26.6 fps
7-zip Benchmark5962 MIPS5917 MIPS

With nothing new on the integrated graphics front, the 890GX relies mostly on its new South Bridge, the SB850, to excite. AMD first doubled the bandwidth between its North and South Bridges. Then, it added a native 6Gbps SATA controller with 6 ports, a Gigabit Ethernet MAC and two PCIe 2.0 lanes. The SB850 doesn’t offer any native USB 3 support, so we’ll still see motherboard manufacturers rely on NEC’s external USB 3 controller. The new South Bridge does support two more USB 2.0 ports as well, bringing the total up to 14.

AMD SB850AMD SB750
NB-SB Link2GB/s Each Direction1GB/s Each Direction
Additional PCIeTwo PCIe 2.0 x1 LanesNone
USB14 USB 2.0 ports12 USB 2.0 ports
SATA6 SATA 6Gbps ports6 SATA 3Gbps ports
PATA2 Channels2 Channels
HD Audio InterfaceYesYes
Integrated Gigabit Ethernet MACYesNo

The first 890GX motherboards will be starting at $130. ASUS' M4A89GTD Pro will sell for $145, add another $10 if you want USB 3.0 support.


ASUS M4A89GTD Pro/USB3

I'd expect Gigabyte's pricing to be somewhere in line with that as well.


Gigabyte's GA-890GPA-UD3H

Ready for Integration

The 8-series of chipsets will be AMD’s last incarnation of traditional integrated graphics chipsets. Sometime next year we’ll get Llano, AMD’s first APU with a CPU and GPU on the same die.


AMD's Llano 32nm CPU/GPU due in 2011

At 55nm, the 890GX North Bridge is tiny. At 32nm the North Bridge would be about 1/3 the size. Now you can see why it makes sense to bring this on-die. The South Bridge is even smaller:


AMD SB750 (left) vs. AMD SB850 (right).

We’re not too far away from having nearly all of this technology integrated into the CPU.

The Test

Motherboard:ASUS M4A89GTD Pro/USB3 (AMD 890GX)
Intel DH55TC (Intel H55)
Gigabyte's GA-890GPA-UD3H (AMD 890GX)
Chipset Drivers:Intel 9.1.1.1020 (Intel)
AMD Catalyst 10.3
Hard Disk:Corsair P256 SSD
Memory:Corsair DDR3-1333 2 x 2GB (7-7-7-20)
Video Card:ATI Radeon HD 5450
Video Drivers:AMD Catalyst 10.3
Desktop Resolution:1920 x 1200
OS:Windows Vista 7 64-bit

The Rest of Clarkdale: Intel's Pentium G6950 & Core i5 650/660/670 Reviewed

Two months ago AMD released a bunch of new CPUs priced between $70 - $120. For the past couple of years AMD has been enjoying the fact that Intel's newest architectures start out at the higher price points, and take their sweet time to trickle down to the common man's socket. With Clarkdale, everything changed.

The cheapest Core i3 is the 530, selling for $113 in 1K unit quantities and around $120 on the street (keepin it real). To paraphrase a short, wise, green man - there is another, even cheaper Clarkdale that you can buy though - the Pentium G6950:

This is a LGA-1156 part based on the Clarkdale core, just like the rest of the Core i3 and dual-core Core i5 line. The chip runs at 2.80GHz, has no turbo support, no AES-NI, no VT-d, no Intel TXT and no Hyper Threading.

ProcessorCoreUn-coreGPUMax Mem ClockCores / ThreadsL3 CacheMax TurboTDPPrice
Intel Core i5-6703.46GHz2.40GHz733MHz1333MHz2 / 44MB3.76GHz73W$284
Intel Core i5-6613.33GHz2.40GHz900MHz1333MHz2 / 44MB3.60GHz87W$196
Intel Core i5-6603.33GHz2.40GHz733MHz1333MHz2 / 44MB3.60GHz73W$196
Intel Core i5-6503.20GHz2.40GHz733MHz1333MHz2 / 44MB3.46GHz73W$176
Intel Core i3-5403.06GHz2.13GHz733MHz1333MHz2 / 44MBN/A73W$133
Intel Core i3-5302.93GHz2.13GHz733MHz1333MHz2 / 44MBN/A73W$113
Intel Pentium G96502.80GHz2.00GHz533MHz1066MHz2 / 23MBN/A73W$87

Intel also disables a portion of the L3 cache, there's only 3MB active on the G6950. The on-package memory controller is also limited to only 1066MHz, while the Core i3s and i5s support up to 1333MHz. Finally its on-package GPU only runs at 533MHz. At a high level, the Pentium G6950 doesn't look too good.

Then again, it lists for $87. Newegg sells it for $96.

The Rest of the Story

To date we’ve only looked at the Core i3 530, 540 and Core i5 661. Since we’re tying up loose ends today we’ll also include results from the rest of the Clarkdale lineup: the Core i5 670, 660 and 650.

The Core i5 660 is just like the 661 we reviewed in January but with a 733MHz GPU clock instead of 900MHz. The 650 is the cheapest i5 Intel offers at $176.

The Core i5 670 is the highest native clocked CPU that Intel ships today at 3.46GHz. It's GPU still only runs at 733MHz though, only the 661 has a 900MHz GPU clock. It's also the most expensive dual core i5 Intel makes at $284. You can get a Core i5 750 for less or a Core i7 860 for the same price. This is clearly a chip for a very specific niche market that needs excellent performance out of two cores and integrated graphics.