Page 1 of 1

KFA2 GTX670

Posted: Sun Jun 24, 2012 6:42 am
by FireFox
Hi

I'm looking at upgrading my old ATi 5850 that has served me well and is still going strong be it overclocked to the max on watercooling.

I'm looking at the KFA2 GTX 670 OC as a possible replacement as I find I need to start to compromise a bit more on quality settings with some new title, still acceptable but usually the tell tell signs of upgrade time.

I'm running a ASUS P7P55D-E motherboard so I know SLi can't be done on this board but I've never ran SLi or Crossfire even thou my last two motherboards could. It just never seems like a viable solution and is more trouble by the sound of it so an irrelevant factor to go ATi/nVidia. Anyways I'm running triple monitors and my res is 5040x1050 without bezel correction.

I can pick up this card for about a $100 less than the 680 but is running the same clock speeds as a stock 680 and is also cheaper than the 7970.

I've been looking and reading reviews and the 670 from nVidia seems to be the current bang for bucks winner. I'm not familiar with the KFA2 brand and the closest priced alternative that would be a better buy is the EVGA 680 SC. I know EVGA is a well know brand but it's a $100 more and the gain is very small if you compare it in clock speeds.

Anyone familiar with KFA2, durability, overclocking stability and so-forth. I'll be watercooling this card with the universal Rasa GPU block I have so I believe I will be able to get some good OC'ing out of the 670 but this is also true for the EVGA 680. Both are in stock at a local supplier so any inputs would be welcomed.

Thanks

Re: KFA2 GTX670

Posted: Sun Jun 24, 2012 9:04 am
by Krom
I've never heard of the brand before, they must be new. Neither Amazon or Newegg appear to carry them yet.

Re: KFA2 GTX670

Posted: Sun Jun 24, 2012 11:02 am
by FireFox
I just realized I might have two problems if I want to upgrade my GFX.

1) My PSU is a Cooler Master Extreme 650W. The requirements for either of the two mentioned cards are 30 - 38 amps on the 12V output. From the link to my PSU the 12v is split into a 12v1 @ 18amps and a 12v2 @ 18amps. I'm confused as to whether this means I have 36 amps on my 12v or 18 amps max. In the latter case It would seem that I might need to replace the PSU first then :?

2) The outputs of the nVidia cards. My LCD's are VGA input only. I have two DVI-i's + one Diplayport connected to run the three LCD's all with VGA adapters. The thing is the DVI-i to VGA adapter, as I just found out, ain't gonna work on the DVI-d that the nVidia is running. So I'm wondering will I be able to run triple monitors (surround vision) via a HDMI to DVI-i via DVI-i to VGA adapter to the LCD as per a quick browse through the suppliers site I could not find a DVI-d to VGA adapter.

My alternative option in more or less of the same price would be the Sapphire 7970. Thou it is more expensive than the 670 it is less than the 680 and is shipped with all the adapters I'll need to get it hooked to my current displays. It does come at a small performance drop off on certain games to the 680 and 670 but it is within the margin of negligible I think. Plus overclocking the 7970 seems to be more straight forward than the new series nVidia cards.

Re: KFA2 GTX670

Posted: Sun Jun 24, 2012 12:45 pm
by Krom
Nvidia stock power target for the 670 is 170 watts, its possible KFA2 have adjusted the GPUs board power targets to achieve their overclock targets so the TDP of their part may be higher.

Perhaps a more useful number would be the PSUs total wattage allocation available on the 12v island, unfortunately cooler master doesn't supply this information. You can take a rough guess by taking the amps times the volts in each island to determine the watts, which leaves your PSU with 432w on the 12v, 150w on the 5v, and 92.4w on the 3.3v for a total of 674.4w. (Note, typically the 3.3v and 5v are on the same island and share their total wattage. Cooler Master is probably assuming ~450 watts on the two 12v rails combined, and the remaining ~200w is shared between the 3.3v and 5v rails.)

Both the CPU and the GPU draw the majority of their power from the 12v rails. So while at stock clocks and power there should be no problem at all, if you do any overclocking you may be pushing the limits of a 650w PSU. (The 2x 6/8 pin PCIe power plug configuration is good for delivering up to 300 watts + 75 more from the PCIe slot itself, so a single video card with that configuration is able to pull a maximum of 375 watts and hitting that is reasonably possible on an overclocked card if it has sufficient on board power regulation. Throw in a overclocked CPU in your system and you could easily blow past 500 watts on the 12v rails, which would require the maximum output even from a typical 750-850w PSU.)

Re: KFA2 GTX670

Posted: Sun Jun 24, 2012 5:00 pm
by AceCombat
IIRC: any DVI-VGA adapter will work with ANY, DVI port to VGA

whether it be DVI-A/D/I

Re: KFA2 GTX670

Posted: Sun Jun 24, 2012 5:20 pm
by Krom
AceCombat wrote:IIRC: any DVI-VGA adapter will work with ANY, DVI port to VGA

whether it be DVI-A/D/I
Wrong: Strictly DVI-D ports don't have the 4 analog pins and cannot support a VGA monitor. DVI-A is analog only, DVI-I supports both digital and analog transmission.

Re: KFA2 GTX670

Posted: Wed Jun 27, 2012 2:16 pm
by FireFox
Okay then found some people vouching for the KFA2 and a review of it as well. Seemed like a good purchase choice till I discovered a little prerequisite that nvidia has for 2D surround vision.

I just found this link and it boils down to that if you don't have DVI/HDMI/Display Ports natively on your screen then your buggered for 2d surround on a single nvidia card, as per my case. So you need to upgrade your displays to something with those connections natively and there is also a big issue that the sync polarity of the screen must be the same. As far as I can tell this isn't the case with the 7970 thou, will just go look for confirmation now in the meantime, so add that to my considering factors as I'm content with my 3x 22" LCD's be it VGA still but to upgrade them for the sake of a GPU makes it way more expensive than just getting a 7970, OC'ing the living daylights out of it (as I'm doing with my 5850 pushing 900mHz) and be on par with a stock 680 imo. The only way for 2D surround with VGA only screens is SLi which doubles the price and my motherboard doesn't support it so no nvidia is again off my shopping list due to technical issues :(

I really thought when they announced 2D surround vision on a single GPU they were back as a option for me but sadly it would seem not to be so. What I find odd is on ATi cards (more specifically sapphire's site) they also mention to operate eyefinity you will need a display port screen but digging deeper in the FAQ off Eyefinity it is clearly stated that connection via an active display port adapter (as I am currently doing) will bypass this, strange that this does not seem to be the case on the green teams side unless the guy who seamed to be a NVIDIA Forums Technical Advisor got it wrong.

Re: KFA2 GTX670

Posted: Mon Jul 02, 2012 9:39 pm
by AceCombat
AceCombat wrote:IIRC: any DVI-VGA adapter will work with ANY, DVI port to VGA

whether it be DVI-A/D/I
ohh.... forgot about that..... :roll: