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Miles 2007-04-14 14:10
The article that got the whole thing going, TomsHardware PCI-Express Scaling Analysis article:
http://www.tomshardware.com/2007/03/27/pci_express_scaling_analysis/
As you can see some pretty sweet hardware can use x1 PCI-E, which is better than regular old PCI because it is faster and each x1 link is on it's own "channel" so it doesn't share bandwidth. Also, as you might have noticed, PCI 6200 cards are hard to come by ($90), whereas 6200/7100GS and 7300LE PCI-E cards are proliferating at $30-40.
So my question is this, can you use this adapter:
http://store.orbitmicro.com/commerce/catalog/product.jsp?product_id=36684
to connect a 7100/7300/6200 to the x1 slots on a
motherboard?
Alternatively I could cut out the back of this connector and let the extra x16 part hang out:
http://store.orbitmicro.com/commerce/catalog/product.jsp?product_id=5484
These nuts (my kind of macadamians :P) overclocked a 7100GS nearly 100% 351/531mhz Core/RAM to 667/750mhz with a lead pencil to lower 2 resistor values and used a bigger heatsink :o .
http://www.vr-zone.com/index.php?i=4124&s=11
Could be fun to try, they even got 36 FPS out of Half-Life 2, looking like this:
http://resources.vr-zone.com.sg/yantronic/7100gs/oc/hlquality.jpg
If you get 2-3 of these cards in one system you can render to a window that spans multiple displays, I managed 3 displays on a 7900GS and the onboard 6150 (PCI-E based on-board still functions when another card is installed), to span 3 monitors at a resolution of 3,072x768. It might be fun to do even more.
What I envision is something like this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128321
It has 2 x16 connectors and 3 x1, if you populated it with 5 7100/7300/6200 series cards you could get 10 displays running :), on one PC, with PCI-E, none of the cards would be on a PCI bus, although you could put in a couple of those PCI 6200 cards and theoretically have 14 displays on one PC.
I know that 4-7 video cards will likely not work, but how about 2 or 3 video cards in a non-SLI motherboard? That surely would be cool. It appears that all the power contacts are in the x1 length bus connector if you consult this drawing:
http://images.tomshardware.com/2007/03/27/pci_express_scaling_analysis/pcie-slot-big.gif
9 ground contacts and 5 12-volt contacts should supply enough power if the motherboard is up to it. I think by the math we might not need any modifications if the 7100 card isn't being over-clocked/over-volted and you connect the fans to a molex instead of PCB power. It is fully possible to put the 12volt power in exclusively through a molex (Hard drive) power cable directly to the adapter board or to a modified card (by cutting the power pins and wiring 12volts directly to the Geforce PCB) As I continue looking into the issue, I see that the motherboard I show is only $80, so with a Glass scraper/razor blade you could cut the back out of the x1 connectors and just let the card extend out the back of the connector, it seems like 1 or 2 x1 cards would fit that way, possibly more on a different motherboard with less in the way. The adaptors could be used on the ones that didn't work. You could test before cutting, but even the cutting will not make the board un-usable (the x1 slots have precious little to fill them, and the ones between an SLI setup are nearly useless anyway to the majority of people :).
The really neat thing with this concept is the ability to scale and the low cost of the video adaptors at this time. The PCI-E specification seems to be fine with full power going through a x1 slot, as that is the design spec. The cards also seem to be fine with running at x1 transfer rate because it is dedicated bandwidth(unlike plain PCI).
An 8800 series over an x1 bus got nearly 70fps on Quake4 at 1600x1200 High quality and 4x Anti-Aliasing, and as you may guess a 7100 series card could not use nearly as much bandwidth and you wouldn't be playing it at levels nearly as high (although you could try ;)
The bare minimum required to try this without irreperable modification to current hardware seems to be:
$25 for the x1 extender (and a razor to cut the back out).
A motherboard with an empty x1 slot (IE practically all PC's with PCI-E support).
A second PCI-E graphics adaptor (possibly borrowed from another PC in the house).
Although if you are really hard-core you could cut out the back on your motherboard PCI-E connector, as long as the board clears any components behind the connector. If it works well a "big picture" choice would be to modify the PCI-E card to turn it into an x1, they could be purchased in bulk, for a reduced price as a group buy, and modified with a dremel to clear any motherboard. Since I believe these cards are currently shipping in new PC's and are upgraded almost immediately by many they are cheap enough to cut into for a long-term solution if they function with testing first.
PS, I love hardware ;P (I suppose you guessed)
Whoo-hoo Nvidia rulez
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Miles 2007-04-15 07:41
Just a small update, according to information on Wikipedia and sites reviewing the 7100, it is an NV44 chip, which makes it a 6200 card.
I just bought a 6200TC 64MB card on ebay for $25 (total including shipping), the plan of action right now is to tape up all but the x1 bus connector and put it the x16 slot on my other PC (when I went from the 3000+ Venice to the 4000+ San Diego I purchased an FIC eMachines motherboard from Compgeeks.com for $50 and made another PC, it has a 6600GT, $63 ebay, in it right now).
If it functions well in x1 mode on that motherboard I can either modify the card or the board to allow the card to plug into a x1 slot on the board.
If that is successful I can then replace the 6600GT in the system and see if the (non-sli) system is compatible with 2 PCI-E cards :D .
I think if successful that this is a much better solution than AGP and multiple PCI cards. The PCI cards share the bandwidth, whereas the PCI-E links are all a separate communication line, The PCI-E bus can also be overclocked in some systems, possibly allowing 300MB/s or more throughput on a PCI-E x1 link.
Cost, the PCI dual-monitor cards are expensive, the "low-end" PCI-E cards are 1/2 or less of the cost and:
Performance, a higher bandwidth connection and some cards sporting 256MB of RAM (the only PCI card I know of with a 6 series GPU and 256MB is $90 at the cheapest).
The main card can be PCI-E for reduced cost over AGP too. I found a $129 (+$10 S&H), 7900GS on eBay right now, so the main 3D single or dual monitor support can be screaming, as I say these mostly clock out to 650mhz with the voltage increase as they are the identical chips to a 7900GTX and that is the GTX stock clock. Or even Dual PCI-E 7900GS and then a couple PCI-E x1 cards of lower output.
The most intriguing aspect is the riser I showed above, if you are willing to use half-height PCI-E cards and make a new I/O plate then this mod is entirely zero-damage to the Motherboard or the card, so both or either are free to be re-sold if need be.
I would love to find a bulk supply of these cards and cut off the PCI-E connector though, just because then no adapters are necessary and any motherboard could be used without clearance issues.
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Miles 2007-04-16 09:49
I have achieved success, I am currently running on an MSI K8N Neo4 with the 6600GT off of the PCI-E x1 slot.
Pictures on Picasa Web album
I got restless (I am home with a stomach flu), so I just grabbed the window scraper and cut out the back of the PCI-E x1 that had room for the overhang of a PCI-E x16 link without hitting any motherboard components.
If you see the above screen capture the drivers correctly identify this as a x1 link. I have yet to do any benchmarking, but I will be trying some 3Dmark to check it out. The bandwidth should be fine :).
I will be getting the 6200 card and will then be able to check that, of course I can also just put the 7900GS OC into this PC, but that would be silly, (and just like me :P).
Beautiful, this PC has no problem so far, I will get back to you on 3D viability.
AM2 MSI motherboards are $54 on Newegg with the integrated 6100, so add 2 cards to that and there is 5 displays (the 6150 offers a DVI and VGA onboard, so 6 displays are possible), of course the integrated graphics are bad, but they are the cheapest motherboards available.
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Miles 2007-04-16 10:32
3Dmark 2001 v.330 is a complete and utter success.
I need to try 3Dmark03 now.
The web album has some screens from the benchmark.
15,714 3Dmarks, that's crazy for a PCI-E x1 bus
Settings/Results Detailed
I couldn't believe my eyes, it is pushing 300FPS, or close to it, in a few tests, and the frames never went below 80 FPS. Keep in mind this is the 6600GT with 128MB GDDR3 RAM and 8 pipes w/3 vertex shaders. A 7300GT GDDR3 would be an ideal card with similar performance, if not greater performance, although it is really a 7600 core.
I just don't know what to say, it is entirely possible that the PCI-E x1 bus is useful for 3D applications and gaming. I wonder if SLI is compatible with the PCI-E x1 bus speeds? Although it would of course prove futile and counter-productive as it causes a reduction in display attachments, and the reduced bandwidth would really handicap the setup.
The real test is in multi-card, multi-monitor setups without SLI.
I hope I can convince at least a few people to try this instead of PCI cards for multiple display.
Shouldn't be too hard considering the price difference.
I also feel sorry for those still on AGP, PCI-E motherboards with integrated Graphics are $5X so just get one. Also 2GB (2x1GB) DDR2 667 (many test out at 800mhz) is available for $99, an AM2 3000+ is only $54.
Of course a Core system is available for $XXX more, I would be considering it if they had any Core Solo processors. Gaming doesn't require 2 cores, and I could afford a Core Solo system. I know they are planning the Celeron 400 series to release what should have been the Core Solo, but if I wait for that there will be Kuma dual cores from AMD that out-perform it, so I plan to go for socket AM2.
PCI-E x1 Rocks your Socks!
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ecarlson 2007-04-16 13:45
Good to know that you can use a regular X16 card in an X1 slot, instead of having to use a more expensive and far less common X1 video card.
- Eric, www.InvisibleRobot.com
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Miles 2007-04-17 06:51
Just a quick chime in, PCI-E 1x is apparently almost twice as fast as PCI, and each link is seperate.
250MB bandwidth stock.
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Miles 2007-04-19 05:33
I just did a control test on the 6600GT, I put it back in the x16 slot and it only made 1,396 more 3DMarks, that is truly impressive for a 93.75% reduction in bandwidth. In other words the card had 6.25% of its original bandwidth and retained 91.84% of its performance in 3DMark01. Really begs the question as to whether you need the card in a x16 slot doesn't it?
Test Results: 3DMark01 6600GT PCIe x16 bus width.
I don't think there is a card similar to the 6600GT for the PCI bus, or this could be a really eye-opening test of PCI to PCIe x1.
Anyone willing to try this with a 6200 PCI and a 6200 PCIe card to give us viable results? You could use tape like TomsHardware did to avoid cutting/damaging your motherboard. Or possibly a software tool, although I don't know of one that reduces the PCIe link width.
I have the XFX 6200TC 64MB DDR2 PCIe here, so I am going to do a benchmark with that. I probably won't be buying a 6200 PCI card unless one is available for $30 (the PCIe card was $25 on ebay, with shipping included).
What might be interesting is to run the test across both monitors with the 6200 and 6600, and then switch them in the slots to see if there is a difference. It would be great to check some 256 and 512MB cards to see if the additional on-board memory reduces the bandwidth necessary.
Ironically TomsHardware ran their test on the 8800 card, which is a card known to require massive amounts of CPU power to control the card, so the bandwidth was taken up with controlling all the stream processors. This is proven out by the higher numbers from the ATI card in their test.
While somewhat useless for our purposes (If you are going to put 3 or more 8800 cards in a PC, use a motherboard with 3 PCIe x16 slots, not to mention a 1KW power supply and the fastest dual- or quad-core CPU you can get, so these x1 speeds are a bit redundant), the tests are nice to know about. It is possible a 7900 series with 512MB of ram is the sweet spot (either a 7900GTX, GT, or 7950GT), possibly even the 7900GS or 7600GT cards, despite the 256mb they have, because of a price between $100 and $150. In fact the 7300GT GDDR3 cards with 256MB may be ideal in the $50 $100 category.
These prices are representative of eBay Buy-it Now deals I have observed in the last month.
x1 Rocks
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Miles 2007-04-19 06:57
I have installed both cards and they function fine.
Here is a screenshot:
Nvidia panel: 2 PCIe cards in a non-sli motherboard.
When I take the screenshot it grabs a 2048x768 screenshot, because both graphics adaptors have one monitor.
I would say that barring heavy gaming on newer titles the cheap 6200 PCI-e setup is a smart buy.
Video and stock exchange type work would be a breeze, and this is much better than a PCI card, because not only is the bandwidth nearly double, think about all the other devices sharing the limited bandwidth on the PCI bus. (Oh, yeah, its cheap too.)
Enjoy, and just say no to PCI kids. :)
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rtangwai 2007-09-23 03:28
I've just finished doing a similar project using ATI cards and got them working quite well. I am running a 6 monitor setup using 3 ATI video cards plugged into an ASUS P5WD2 Premium motherboard (Intel 955X chipset) with 2 x16 PCI-E slots and 1 x1 PCI-E slot. Previously I had made it work in XP using an X800XL CrossFire Master and 2 Radeon 9200 PCI boards. To work in Vista's Aero Glass *ALL* the video cards have to use the same Catalyst driver and for practical purposes has to use PCI-E, so I took a crack at it by buying a new Sapphire X1950Pro 256MB and a used Sapphire X800XL 256MB and sitting down with a knife.
Like Miles I had to cut out the back of the PCI-E x1 slot. Unlike Miles I had the unfortunate luck that something was blocking the back of the PCI-E x1 slot - the CMOS battery. I notched both sides of the CMOS battery holder, bent the negative pole contacts away, then wired up a 3v Li-ion CMOS battery from an old laptop. That gave me enough clearance to make the card fit. A useful bonus was that the bottom of the battery holder does not quite touch the bottom of the video card so it helps support the card when installing.
Net result: Sapphire X800XL running on x1 lanes, ATI X800XL CrossFire Master running on x2 lanes. The reason for x2 is that the P5WD2 motherboard has 2 x16 slots, but only 20 PCI-E lanes. The primary slot runs at x16, the secondary slot at x4 *ONLY* if the teriary x1 slot is inactive, otherwise the secondary runs with x2 lanes and the teriary x1 lane.
Haven't installed Vista yet to try it out in the new setup, but XP Pro sure likes it - I've noticed the secondary and teriary monitors no longer show a slower interface when moving windows around.
To summarize: Miles's technique applies to ATI X800XL cards and Intel 955X chipsets too. Kudos to Miles for giving me the hints necessary to make it happen and save me $250 on a new 680i motherboard :)
Robert A. Tang-wai
Chief Technology Officer
reBOOT Canada
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ecarlson 2007-09-23 08:19
Thanks for the additional information.
- Eric, www.InvisibleRobot.com
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