AMD 890GX Chipset Review - PAGE 1

It hasn't been a long time since AMD launched the 785G chipset, featuring the integrated ATI Radeon HD 4200. As we have seen, this IGP has many great features packed in it, including DirectX 10.1 support, audio via HDMI and Unified Video Decoding 2. The only thing that left me wanting more is that the older HD3300 at the heart of the 790GX chipset was still stronger than the HD4200 in gaming, due to its 200Mhz higher frequency. I was then wondering that, if the 790GX is an updated 780G, would AMD release an updated HD4200, something along the lines of an 795GX?

Then came the Clarkdale processors from Intel featuring an IGP clocked at 733 or 900MHz, which in our tests proved to perform better than the HD4200 in gaming. A few days later, AMD announced it would soon launch the first of its new series chipset. Today is when we get to see this updated HD4200 I was hoping for; the 890GX houses the HD4290, featuring a 200MHz higher clock. How will it compare to the Clarkdale IGP? Will AMD get back its title of the best IGP all around? My first guess is that this is very probable, since the HD4200, clock-for-clock, is still faster than Clarkdale. But we will find out either way, today.

The 890GX is not much different than its predecessor physically; the IGP has the same 40 unified shaders with a 128bit memory interface, and has the ability to use a 128MB DDR3 sideport memory. What differentiates it though are the PCI-E lanes. Whereas the 785G would only run two PCI-E slots at x16/x4, the new chipset can do x8/x8 so a second video card will not be bottle-necked as much. Of course, if only one video card is installed, it will run at x16. Furthermore, the HD4290 can run in Hybrid CrossfireX mode with the HD5450 videocard. The following picture is that new 890GX northbridge and its sideport memory chip, on the ASUS M4A89GTD PRO /USB3.

The other main difference is the connection between it and the southbridge; the Alink Express bandwidth has been increased from 1 to 2GB/s. This was a smart move since the new SB850 supports SATA III(6Gbps) natively on all of its six ports, which has in turn double the bandwidth of the previous generation. This makes AMD the very first chipset manufacturer to offer this technology without the need for a discrete controller. This is just not comparable to the latest Intel chipsets, which are only equipped of first generation PCI-E x1 connections to connect external controllers, thus bottle-necking the SATA III and USB 3.0 at a low 250MB/s, unless a bridge is used to make up one PCI-E 2.0 from two 1.0 lanes, like on the ASUS P7P55D motherboard.  Back to the SB850, USB 3.0 has not been implemented unfortunately, but AMD did however add two PCI-E 2.0 lanes to the southbridge, so properly implementing a discrete USB 3.0 controller is a kid's game. Therefore, most boards will probably have only two USB 3.0 ports because this is what the controllers provide.

It is also important to note that Mozilla Firefox 3.7 will most probably feature the Direct2D API (the alpha already does). Web pages based on Adobe Flash will be rendered much faster, benefitting from GPUs such as the HD42xx family for hardware-accelerated 2D rendering.