https://xboxdevwiki.net/api.php?action=feedcontributions&user=Dans34&feedformat=atomxboxdevwiki - User contributions [en]2024-03-29T11:18:41ZUser contributionsMediaWiki 1.28.0https://xboxdevwiki.net/index.php?title=NForce&diff=6683NForce2019-01-25T09:59:09Z<p>Dans34: Slight AMD Heritage correction</p>
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<div>{{retrieved|http://www.xbox-linux.org/wiki/NForce}}<br />
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This documents collects information about the Xbox chipset and its sibling, the nVidia nForce chipset, as well as further relatives.<br />
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== nForce ==<br />
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The nForce chipset consists of the IGP (Integrated Graphics Processor) Northbridge and the MCP (Media and Communications Processor) Southbridge. Both are available in different flavours:<br />
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<br />
* IGP-64: 64 bit memory bus<br />
* IGP-128: 128 bit memory bus (TwinBank), requires two DIMM modules for 128 bit operation<br />
* MCP-D: includes Dolby Digital encoder<br />
* MCP: Dolby Digital encoder disabled<br />
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So these are the four possible combinations:<br />
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<br />
{| class="wikitable"<br />
|-<br />
| <br />
| MCP<br />
| MCP-D<br />
|-<br />
| IGP-64<br />
| nForce 220<br />
| nForce 220D<br />
|-<br />
| IGP-128<br />
| nForce 420<br />
| nForce 420D<br />
|}<br />
[https://web.archive.org/web/20100617023830/http://www.theregister.co.uk/2001/05/31/nvidia_crush_chipset_named_nforce/]<br />
[https://web.archive.org/web/20100617023830/http://www.theregister.co.uk/2001/06/01/nvidia_crush_is_called_nforce/]<br />
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The VGA controller inside the IGP is a "GeForce2 MX Integrated Graphics" (PCI ID:10de/01a0). Its internal name is NV1A.<br />
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[https://web.archive.org/web/20100617023830/http://pciids.sourceforge.net/iii/?i=10de]<br />
[https://web.archive.org/web/20100617023830/http://www.nvitalia.com/articoli/editoriali/produzione_nvidia_2001.htm]<br />
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Although IGP-64 and IGP-128 are different and their respective chipsets have different codenames (Crush11 and Crush12, see below), there seems to be no difference from the software side:<br />
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* The VGA BIOS of the MS-6367 mainboard (nForce 420D configuration, i.e. Crush12) has the internal name "CR11BT.ROM". It also includes the strings "NVIDIA GeForce2 Integrated GPU", "CR11 Board" and "Chip Rev B2".<br />
* The PCI IDs seem to be the same for the GPUs inside IGP-64 and IGP-128.<br />
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== Crush ==<br />
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"Crush" was the codename of the nForce chipset. Crush11 is the nForce 220/220D/230/230-T, Crush12 is the nForce 420/420D/430/430-T, and Crush18 is the nForce2. The "11" probably derives from "NV11", the internal name of the GeForce2 MX.<br />
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[https://web.archive.org/web/20100617023830/http://users.erols.com/chare/chipsets.htm]<br />
[https://web.archive.org/web/20100617023830/http://www.theregister.co.uk/2000/11/17/nvidias_super_secret_crush_spec/]<br />
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== nForce &amp; Xbox ==<br />
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The Xbox has an IGP-128 that uses an NV2A video core (PCI ID:10de/02a5), which is between the GeForce3 (NV20) and the GeForce4 (NV25). The Southbridge is called "MCP-X" and lacks the PCI card bus (PCI bus #1).<br />
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[https://web.archive.org/web/20100617023830/http://www.digit-life.com/articles/nvidianforce/]<br />
[https://web.archive.org/web/20100617023830/http://www.anandtech.com/showdoc.html?i=1484]<br />
[https://web.archive.org/web/20100617023830/http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=1535]<br />
[https://web.archive.org/web/20100617023830/http://www.anandtech.com/systems/showdoc.aspx?i=1561&amp;p=3]<br />
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== AMD Heritage ==<br />
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There is the following rumour, which is not fully verified yet:<br />
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* Microsoft wanted AMD to make the CPU and the chipset for the Xbox, and nVidia to make the video hardware.<br />
* When alpha hardware had already bee built, Intel made a better deal<br />
* Microsoft agreed to have Intel CPUs; Intel had to modify AMD's chipset to support an Intel CPU<br />
* Intel insisted that the brand name AMD could not be associated with the Xbox, so nVidia licensed the AMD chipset. Now the Xbox chipset was by nVidia.<br />
* nVidia sold the same chipset for PCs, calling it "nForce".<br />
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This is the reason why<br />
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* the Xbox is the only nForce chipset with an Intel CPU<br />
* the AMD chipset and the nForce chipset are so similar<br />
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Evidence:<br />
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* The AMD and nForce AMD IDE controllers are fully compatible. (Linux kernel: "AMD 755/756/766/8111 and nVidia nForce/2/2s/3/3s/CK804/MCP04 IDE driver for Linux." [https://web.archive.org/web/20100617023830/http://lxr.linux.no/source/drivers/ide/pci/amd74xx.c])<br />
* The I2C/SMBus controller on the nForce is fully AMD-756/766/68 compatible. [https://web.archive.org/web/20100617023830/http://lxr.linux.no/source/drivers/i2c/busses/i2c-amd756.c]<br />
* The audio controller is i810 compatible - as is the audio controller of the AMD-768 and the AMD-8111.<br />
* The nForce and AMD-768 modems are compatible.<br />
* At least one register ("VGA_en") in the nForce PCI-to-AGP bridge is compatible with the AMD chipset (AMD-761, 24081.pdf, page 136).<br />
* The nForce uses HyperTransport.<br />
* [https://web.archive.org/web/20100617023830/http://www.uwsg.iu.edu/hypermail/linux/kernel/0307.3/0922.html], [https://web.archive.org/web/20100617023830/http://www.uwsg.iu.edu/hypermail/linux/kernel/0301.3/0305.html]<br />
* ''"One man's guess, the silicon is not a major factor. Because the nForce and 760 MP have a similar pin count, they are going to be cost comparable."'' [https://web.archive.org/web/20100617023830/http://overclockers.com/articles446/]<br />
<br />
{| class="wikitable"<br />
|-<br />
| <br />
| Northbridge<br />
| Southbridge<br />
|-<br />
| AMD-760<br />
| AMD-761<br />
| AMD-766<br />
|-<br />
| AMD-760MP<br />
| AMD-762<br />
| AMD-766<br />
|-<br />
| AMD-760MPX<br />
| AMD-762<br />
| AMD-768<br />
|}<br />
[https://web.archive.org/web/20100617023830/http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_873_1133,00.html AMD-760™ Chipset Tech Docs]<br />
[https://web.archive.org/web/20100617023830/http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_739_1130,00.html AMD-760™ MP Chipset Tech Docs]<br />
[https://web.archive.org/web/20100617023830/http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_873_4296,00.html AMD-760™ MPX Chipset Tech Docs]<br />
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The nForce chipset might be based on the AMD-760 chipset.<br />
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== More Links ==<br />
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[https://web.archive.org/web/20100617023830/http://www.duxcw.com/digest/guides/mb_chip/nforce/print.htm]</div>Dans34