780G, err 790GX Northbridge
The biggest change AMD made in designing the 790GX is an increase in core clock speed from 500MHz to 700MHz. In essence, AMD is speed binning the 780G chipsets and those that pass end up with a 790GX silkscreen stamp. Due to the improved performance, the graphics processor also has a name change bump from Radeon HD 3200 to, wait for it, Radeon HD 3300.
The 790GX still utilizes a 55nm TSMC half-node process with transistor counts hitting 205 million. The Northbridge contains 26 lanes of PCI Express 2.0 connectivity with 16 lanes reserved for graphics via a single x16 link or a dual-x 8 CrossFire configuration. Six lanes are available for x1 links for expansion slots or onboard peripherals. AMD reserves the remaining four links for use in the A-Link Express II interface to the SB750 Southbridge.
Hybrid CrossFire returns but support is still limited to the HD 2400 and 3400 based cards. The improved clock speeds of the HD 3300 and performance cache allows a user with a HD 3470 to get performance near that of a HD 3650. The problem is that most HD 3470 cards are selling for around $50 and recent price reductions have brought the price of the HD3650 down to $65, in essence negating the previous price to performance advantages. We doubt anyone will take advantage of this feature since the chipset is targeted primarily for the performance sector where most users will take advantage of a single performance oriented card like the HD 4850 or a CrossFire configuration instead of Hybrid CF if the integrated graphics were not fast enough.
Sideport Memory returns energetically in the 790GX products, this time at the request of AMD. While an option on the 780G boards, AMD has persuaded the motherboard suppliers to include sideport memory in at least one 790GX product from their lineups. Along with this inclusion comes a new name, Performance Cache. The performance cache resides on a 16-bit memory interface that can utilize DDR2 or DDR3 memory. The majority of motherboard makers will use DDR3-1333 in a 128MB configuration. While performance between DDR2 and DDR3 is about the same in this particular application, DDR3 offers additional power savings.
Depending on the processor and HT Link utilized, sideport memory will generally improve performance across the board up to 5% - not just in games, but in video decoding capabilities as well. Besides performance improvements resulting from the local frame buffer instead of shared system memory, the new driver design allows improved Deep Sleep capabilities with the active frame buffers being stored in the performance cache.
As with the 780G, the 790GX AMD features Unified Video Decoder 2.0 (UVD 2.0) capabilities that include hardware acceleration for decoding VC-1, H.264 (AVC), WMV, and MPEG-2 sources up to 1080p resolutions. Advanced de-interlacing is available when using a Phenom processor. HDMI 1.3 compliance continues with xvYCC color space support and 4:2:2 capabilities. On the audio side, the HDMI interface offers support for 2-channel LPCM, Dolby Digital 5.1, or DTS 5.1. AMD still does not support Multi-Channel LPCM and it continues to be a thorn in our side.
Rounding out the video capabilities of the 790GX is analog output, DVI/HDMI interfaces, internal or external TMDS, and integrated DisplayPort capabilities. The HD 3300 features dual independent displays that allow resolution, refresh rates, and display data to be completely independent on the two display paths. AMD provides HDCP support with on-chip key storage for DisplayPort, DVI, or HDMI interfaces but it is regulated to a single interface during playback operations. ATI SurroundView is fully supported when utilizing a Radeon based discrete card that allows the system to drive up to four monitors.
The Radeon HD 3300 graphics processor features a DX10 compliant unified shader model 4.0 graphics core. This architecture contains 40 stream processors from two shader SIMDs. The core features 128-bit floating point precision for all operations, a command processor for reduced overhead, DXTC and 3Dc+ texture compression, texture support up to 8192x8192, and a fully associative texture and Z/stencil cache.
The single texture and ROP units are capable of handling four texels and pixels per-clock, respectively. This allows up to 16 texture fetches per clock cycle and up to 128 textures per pixel. The one modification AMD made compared to the RV610 core on the HD 2400 series is the vertex and texture caches are fully associative instead of separate. Other technical goodies include early Z-test, Re-Z, Z range optimization, and Fast Z-clear operation.
There are eight render targets (MRTs) with anti-aliasing support, along with lossless Z and stencil compression. The HD 3300 features multi-sample anti-aliasing (up to 4 samples per pixel), custom filter anti-aliasing, adaptive super-sampling and multi-sampling, along with Super AA when using Hybrid CrossFire. HDR rendering is supported for all anti-aliasing features, although like current HD 2400 products, the performance hit for using AA is significant in certain games.
Texture filtering features include 2x/4x/8x/16x adaptive anisotropic filtering modes with up to 128 taps per pixel support. Bicubic, sRGB, and percentage closer filtering are featured along with 128-bit floating point HDR support. Finally, the HD 3300 includes a programmable tessellation unit and an accelerated geometry shader path for geometry amplification.
Let’s move on the biggest improvement since sliced bread, well almost.
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mpjesse - Friday, August 22, 2008 - link
Did the writer get sick? Did he DIE? 2+ weeks to benchmark an integrated chipset? Practically the entire galaxy has already reviewed this chipset. I'm starting to get tired of both the physical speed (or lack thereof) of this website and the quickness (again, lack thereof) in which crap is published.-Fed Up
bravomail - Wednesday, August 20, 2008 - link
Here is the article with the pictures (in russian unfortunately)http://www.riddik.net/publ/1-1-1-25">http://www.riddik.net/publ/1-1-1-25
The guy ripped apart AMD BE CPU only to find out some bubbled thermopaste between chip and attached lid.
Use Google translate to read this story.
computerfarmer - Tuesday, August 19, 2008 - link
It is now the 19th of August, perhaps the review is coming soon?Beta BIOS was on the 13th of August.
Waiting
Waiting
Waiting...................
OCedHrt - Thursday, August 14, 2008 - link
With all this advancement in IGP, why does Hybrid Crossfire only work with low end cards? I would love to be able to use it with a 4850 or 4870 where the IGP switches completely over to the discrete as needed.MikeODanyurs - Sunday, August 17, 2008 - link
The new DFI 790GX card states it has Hybrid CrossFire that will work with HD 3850 and I believe will even work with the IGP with 2 cards.someguy11 - Wednesday, August 13, 2008 - link
"unless AMD can implement something akin to HybridPower from NVIDIA, which allows the discrete card to power down and switch to the IG unit at idle for less demanding tasks like Office Applications or Bejeweled. Otherwise, the IG unit and all of its potential benefits are wasted with a discrete card setup"Does anyone know if the implementation of something like HybridPower from AMD on the current day 790GX boards is possible?
In other words, if I buy a 790GX will a power saving feature where the discrete card can be powered down be simply a BIOS flash or will new boards have to be made (assuming AMD develops something along this route)?
I ask b/c this "power down" feature really interests me and if this can be implemented via a BIOS upgrade, then I am more apt to get a 790GX today rather than a 790FX board who knows when. I also like the idea of having a board with onboard IG so you can play the graphics card price wars when you want to.
Thanks for the help!
ZootyGray - Tuesday, August 12, 2008 - link
There are lots of unbiased websites offering useful reviews. I am sick of waiting for your uncompleted works and biased results.Your review of 4870x2 is the end of the line - that is the worst trash I have seen.
Why would anyone want to wait for you to trash more AMD hardware.
Save your energy for yourself. I do not need your self-importance.
Maybe when you can followup on last May's 780G review, as promised, I might be interested - until then - I apologize for thinking you were some kinda good review place. Yer out. Bias is not quality. It's abuse. Not your victim anymore.
computerfarmer - Saturday, August 9, 2008 - link
On page 2 it is noted as saying the new 790GX graphic is set(default) at 700mhz compared to the 780G at 500mhz. The manual for the Gigabyte GA-MA790GP-DS4H (rev. 1.0) page 42 has the default set at 650mhz. This leads me to believe that side by site tests from different manufacturers should show differences based on default settings. Also SidePort memory ratings need some attention. If SidePort is DDR3 at 1333mhz and system memory is at 800/1066mhz then how do they function together at different speeds? Or is the SidePort memory speed based on system memory up to 1333mhz?Thank you Anandtech for such an informative article.
maree - Friday, August 8, 2008 - link
Quoting from the article"For the multimedia user, ... The SB750 does offer ACC and along with it the opportunity to run lower voltages ..."
Does it mean motherboards running on this chipset can take a phenom 9550/9850BE an turn off 2 cores then expect the power performance of amd 4850e?
ZootyGray - Thursday, August 7, 2008 - link
I really don't want to go dig up exact quotes from previous reviews."The Three Amigos" review revealed "pop goes the mosfet" issues with products produced by various mobo manufacturers. I really liked that review - BUT - a followup was indicated as coming - and it never appeared.
This review ends in a similar manner.
And the Foxconn review seemed to really sidetrack and resulted in 3 articles; and for my little brain, I found it difficult to follow the coherence of the whole thing.
Now we have a whole new chipset and a bunch of mobos you say you are benching soon. Ok, so that makes sense - assuming this will actually happen soon. No problem there.
BUT - there's this really interesting comparison to 780G which you are presenting. I wonder what happened to the mosfet issue that you so beautifully revealed. I wonder - Is it in play here as well? I DOUBT that! This is a performance board - right?
BUT - are you trying to lead some people to buy the original 780G boards regardless of resolution (if any) of the "pop goes the mosfet" issues. And asus has produced new mobos that clain 125watt handling power - ie no "pop"???
I think all this uncertainty might be dangerous for some people with great expectations.
I think some unfinished business should be clarified.
I think some comment on 'mosfet' should be included in these upcoming benchies.
I think this might be misleading a lot people - and your unfinished work is a little underhanded slight on AMD products. I REALLY HOPE you clear this mess up; since it was your baby to start with - and that was good. And that caused me to respect Anandtech.
Please don't leave me just hanging on and waiting - I doubt I am the only one. I would prefer completion rather than assuming this is another antiAMD site, and have to go elsewhere. It's your credibility, for me, at least, at this point.
Golf taught me that follow through is a big part of the golf swing. I know you are busy. Some loose ends can bite you. How close IS this to the 780G boards anyway? Has the "pop" been fixed?
I hear Vanilla Fudge "Keep Me Hanging On" playing in the background - wow, it has been a while since I heard that.
Thank you.