Print 18 comment(s) - last by Trevor311.. on Mar 1 at 8:57 PM

NVIDIA A01 Spin of MCP55P
The next generation NVIDIA core logic aims to be the company's most ambitious yet

NVIDIA has been quiet about core logic since nForce4 x16 was launched a few months ago, but the company is rapidly approaching on final silicon for the MCP55 family.  MCP55, as we reported previously, is the nForce4 successor dedicated to Socket AM2/S1 motherboards.  Our sources in Taiwan have just confirmed with us that MCP55 spin A02 is available to manufacturers and is already implemented on working motherboards.  The A01 spin has been floating around on engineering samples since January.  Traditionally, A02 and A03 spins end up in the market place on retail motherboards.

Unfortunately, MCP55 is a far cry from a revolutionary chipset.  According to NVIDIA roadmaps, it contains a different audio codec, dual Gigabit Ethernet PHYs and can use six SATA channels instead of four, but the core logic is still hampered by the fact that it takes two chipsets to control a 2x16 SLI setup.  The majority of games today cannot take complete advantage of 2x16 SLI yet, but adding two Northbridges to the motherboard to enable 2x16 seems like an incredible waste of money (particularly when the interconnect between the two bridges is only exactly enough for than the actual x16 PCIe bus, even though there are other devices on the controller). 

ATI's still unreleased Xpress 3200 (RD580) core logic can support 36 PCIe lanes on the Northbridge.  Recent roadmaps revealed that a stripped down version of RD580, RD550, will compete directly with MCP55P with 2x8 PCIe lanes rather than a full 2x16 for multiple GPU support.

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By kilkennycat on 2/27/2006 6:37:37 PM , Rating: 2
On an AMD board, nF4 X16 employs an additional Northbridge plus the usual Southbridge. On an Intel board, a Northbridge and a Soutbridge, which would both be needed anyway. I don't get this "2 Northbridges" statement. Also the interconnect between the 2 chips is X16 full-duplex, exactly the same as the PCIe X16, not less as implied in the article. Kris, in the hurry to publish the latest news, please get the technical facts straight. I respect you and Anandtech for your normal technical accuracy... please don't sacrifice this accuracy in the haste to publish a news article.

By KristopherKubicki on 2/27/2006 7:01:16 PM , Rating: 3
The NF4 X16 is composed of a CK804 and a C51 MCP. Both can be used as northbridges and both technically are. Whether or not they are designated as a south bridge or a north bridge is really not significant.

The interconnect between the two chips is a 2000MHz HT link, which is capable of 4GB/s in each direction. Several manufacturers actually limit the interconnect to 1000MHz for some reason, but that is a whole different issue. Regardless, if there was nothing else on the southbridge, the second PCIe x16 card could saturate the link between the two core logics... but NVIDIA also puts the SATA, PCI and Gigabit PHY on that bus as well. This is why I said the transport bus between the two chips is not all it could be.


By kilkennycat on 2/28/2006 2:19:45 PM , Rating: 2
Kris, thanks for improving the accuracy of the text in the article with regard to the bandwidth between the 2 chips in the nF4 X16 pair.

By kilkennycat on 2/28/2006 2:30:10 PM , Rating: 2
"....but adding two Northbridges to the motherboard to enable 2x16 seems like an incredible waste of money....."

The actual SLI chip-set counts are as follows:-

nF4 SLI X16 nF4 SLI ( X8 )
AMD 2 bridge chips 1 bridge chip
Intel 2 bridge chips 2 bridge chips

By Trevor311 on 3/1/2006 8:57:02 PM , Rating: 2
Ok, question then...I have an nForce 4 x16 system (Asus A8N32-SLI Deluxe) with 4 SATA drives (1 Raid-1 and 1 Raid-0) on the nvRaid chip, 2 7800GTX cards in SLI, and an SB X-Fi Fatal1ty card (PCI).

Would this interconnect bandwidth limitation be a possible cause for the X-Fi exhibiting static/crackling/hissing? (doesn't appear to happen when playing back MP3s, only when I'm playing WAV or playing games). There's a TON of users posting in the Creative forums about this problem, not all of them are using the same chipsets, etc., but many of them are using x16 mainboards with SLI graphics cards.

Sub-headline doesn't match body of article?
By joey2264 on 2/27/2006 2:23:18 AM , Rating: 2
You say that "The next generation NVIDIA core logic aims to be NVIDIA's most ambitious yet", and then you say in the article, "Unfortunately, MCP55 is a far cry from a revolutionary chipset" Which is it?

Personally, I am going to wait for RD580, especially if Tuesday's launch is an unimpressive as I suspect it will be.

By KristopherKubicki on 2/27/2006 2:27:59 AM , Rating: 3
Well it is NVIDIA's most ambitious core. I just wouldn't call it that great on paper.

I'm with you on RD580.

RE: Sub-headline doesn't match body of article?
By Discord on 2/27/2006 2:38:40 PM , Rating: 2
LOL, you'll still have a crappy ass SB solution when the RD580 finally appears. I guess I'll hold out until the Ati 650 (Is that correct? It's a 450 now, right?) comes out.
Of course, by the time that happens, NVIDIA might have a 40-lane single chip solution with all of the Ali/Uli improvements.
Hey, I can dream can't I?

By bob661 on 2/27/2006 5:32:56 PM , Rating: 2
you'll still have a crappy ass SB solution when the RD580 finally appears
They didn't upgrade the SB?

Just admit it
By Lakku on 2/27/2006 1:40:39 PM , Rating: 2
Just admit it AT, come out and say this chipset is ambitious then you claim it to be a piece of crap cuz it still uses 2 chipsets apparently (which so far, makes not one iota of difference), and then add on, since you left it out, that you love ATi and want to go to bed with R580 and RD580. Seems a bit silly to slam a product before it launches and to repeat at least 10 times a day how awesome ATi is and how awesome it is they finally launched a product on launch day after almost a year of trying.

RE: Just admit it
By DigitalFreak on 2/27/2006 3:20:55 PM , Rating: 2
Fanboi alert!!!

RE: Just admit it
By bob661 on 2/27/2006 5:34:51 PM , Rating: 2
Fanboi alert!!!
Doesn't sound like a fanboi to me. He sort of makes a point.

who cares about sli,
By 8steve8 on 2/27/2006 2:47:18 AM , Rating: 2
well 6x sata is nice, especially for raid5 people...

as for 2xSLI, ppl who are buying two video cards can pay a few dollars more per mobo for an extra chip...

who cares.. i mean really what percentage of people actually have 2 video cards in their systems right now?

and the reality is a single video card is just about always a smarter choice per $. (and per watt)

RE: who cares about sli,
By dcollins on 2/27/2006 3:56:50 AM , Rating: 2
But, in reality, there's a lot of people that want the fastest, not the smartest. And, much of the draw of SLI from nVidia's perspective is the publicity; it looks good to have the most powerful solution regardless of cost.

And, beside, why would you buy a motherboard with such a limitation if you could find a similarly priced product that does not (i.e. an ATI chipset)? So much of the enthusiast market is about percetption.

Different Audio Codec?
By Plasmoid on 2/27/2006 7:38:50 AM , Rating: 2
Obviously not the return of sound storm but the end of realtek in nforce?

Anyone know what they plan to use this time round?

RE: Different Audio Codec?
By Dahak on 2/27/2006 7:59:04 AM , Rating: 2
I remember reading somewhere that they are finally adding hd audio (intels azalia(sp?) support.
As for realtek in nforce, thats up to the board maker as it has the ac97 hooks in the chipset.

By DigitalFreak on 2/27/2006 12:56:47 PM , Rating: 2
"(particularly when the interconnect between the two bridges is slower than the actual x16 PCIe bus)"

That's pretty stupid. I had though they would bump up the interconnect bandwidth to 10GBps or so.

46 PCI Express Lanes
By thomasxstewart on 2/28/2006 6:10:01 AM , Rating: 2
<C51XE+MCP55PXE:/b> Epox mainboard pictured here: 9NF4SLI2 is 46 PCI Express lanes & was removed before marketing series of 3. Lower two are 20 & 32 lane. So Xpress 3200 or C51XE+MCP55PXE: have 36/46 PCI Express lanes, yet no Mainboards are roadmapped. That is Manufacturers COLLUSION & Illegal. Also, with so much PCI Express 16X SLI trouble, 36+ lanes are mandatory just to stop excess controller heat.X9XX series cards in 512 mb need 700+ watt PSU. Thats just too much for system.Signed:PHYSICIAN THOMAS STEWART VON DRASHEK M.D.

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