Jump to content
Latest News
  • Apologies for the downtime. We had to update our backend and theme.
  • We will continue pushing updates.
  • Apologies for the downtime. We had to update our backend and theme.
  • We will continue pushing updates.
  • NVIDIA GTX 1080 PCB Run Down


    Brian

    With NVIDIA having now officially launched their next generation Pascal based GTX 1070 and 1080 GPUs, there are a number of AIB partner boards coming to the market soon. We have a video today by YouTuber Actually Hardcore Overclocking that examines different custom PCBs and helps break down the differences between the various boards and their power delivery designs. If you've read about additional power phases that will be available on AIB cards that are lacking in Founder's Edition but never quite knew what that meant, this video should help. 

     

     


        Report Article


      User Feedback


      This guy mostly knows what he's talking about. He was right in ignoring the number of PCI-E power connectors. Those have zero impact on overclocking and more just makes the card more power efficient. He did properly identify phases, which many people don't, but he did annoyingly use the recent Nvidia nomenclature defining phases which is misleading. Ex. when saying 8+2 he's saying there's 8 core phases and 2 memory phases. This is only the recent meaning of that phrase. In the past 8+2 meant you have 10 core phases, with 8 switching in sequence plus another 2 switching in their own sequence, both summing up to deliver current to the core. For example the ATI 4890 was a 3+2 configuration for the core. Minor thing, but using Nvidia's misleading marketing terms annoys me.

       

      For bigger things that I think he did wrong, he ignored cap quality and vdroop. Many "overclocking" cards try to have big impressive looking phases with big electrolytic caps that look cool. The problem is of the 3 main cap types you can have the big radial electrolytic caps are the lowest quality. Surface mount electrolytics tend to have superior ESR (effective series resistance. this matters for sudden load changes, or a phase switch) than the round radial electrolytics, but are more expensive and look less cool. Radials do tend to have higher capacitance than SMD, but usually electrolytic capacitance is overkill by nearly an order of magnitude on "overclocking" desktop cards, with ESR being more of a limiting factor. Even better ESR are ceramic caps, but these are the smallest and most expensive. Many of these boards completely lacked ceramic caps for the core on the front of the pcb. Maybe they made up for it on the back, but its obvious that many manufacturers are trying to make their boards look cool.

       

      As for vdroop, many of these boards screwed over the memory. All high phase count cards except the zotac threw the memory phases way to the right of the card. This gives the current a long distance to travel, and even worse is the current needs to travel under the core phases, which will already be using many pcb layers. This also hurts core vdroop because pcb layers that the core would otherwise receive are needed to route the memory power. Then add in that 3 memory chips also have data and address lines between the core and power phases, and you have one overly worked pcb.

       

      In short, the ASUS looked like crap to me. No top side ceramic caps and no SMD electrolytics. The powercolor card looked good for air and H20 with a good ceramic cap count, but seemed to lack the FETs to push the current or LN2. The EVGA should be good for LN2 if the backside makes up for the front side's lack of ceramics. Its electrolytic count is insane with tons of SMD caps, but it looks like it will have vdroop problems. The MSI looks decent with a good chunk of ceramics and high phase count, but lacks SMD electrolytics.

       

      I don't get why he gave the Zotac so much crap. This card looked to be the best to me. That memory phase location is great. The PCI-E slot can route current up the left side so it can get a strong 12V connection that avoids messing with the core power side of the card and memory data and addressing. The Zotac will have the best vdroop of any card. It has a good count on ceramics and a few SMD electrolytics. Yes the FETs COULD be poor, but they could also potentially be better than the high/low combo chips on most cards.

       

      Honestly the 25A high/50A low chip that he said Nvidia is using sounds like crap. Having a lower high side current limit than low side makes no sense. Yes high side conducts current way less often than low side so you want a smaller faster switching FET, but if you exceed that 25A the FET can still blow up. If the low side conducts 50A when it is on, then the high side also conducts 50A, so this chip is only rated for 25A due to the high side. I can see why manufacturers would avoid this chip. I'm surprised I didn't see the TI 83750 high/low combo chip on any cards as this has a 40A rating and is very commonly used on mobile cards.

      Share this comment


      Link to comment
      Share on other sites


      Create an account or sign in to comment

      You need to be a member in order to leave a comment

      Create an account

      Sign up for a new account in our community. It's easy!

      Register a new account

      Sign in

      Already have an account? Sign in here.

      Sign In Now


    1. Similar Content

      • By 71hourahmed
        I'm looking at finally upgrading my m17x from its old 7970m to a 980m, but the person I contacted to buy the card from warned me that the 980m requires a 200W power supply, and win10 (I'm still on 7, but I can upgrade easily enough, so that shouldn't be too much of a problem).
         
        I have read that the 7970m only required 100W, so I have no idea if my laptop would even be able to power the 980m or whether this would just be a waste of several hundred pounds. Can anyone clarify?
         
        Also, I have read on here that installing a new card in an m17x require you to manually update the video drivers, but I'm afraid that I'm not quite sure what that means, exactly - would I need to rely on kindly users on here to keep uploading new modded versions of the video drivers in perpetuity, or is it just that I need to somehow tweak the installation on new drivers in future?
      • By Polip
        Hello I'm lookig for 870m performance vBIOS, any possibilities for help ?
      • By Rappid Rabbit
        i was wanting to upgrade my clevo p151sm1(not -a) that has a gtx 765m to a 970m or 965m and wondering if its possible to do before i go buying the gpu and have it not work (cpu is i5 4300m)
      • By RandyTucker
        Having pondered over a eGPU build I instead decided to put my GPU inside my 15.6 laptop by extending the laptop base. I have a Dell optiplex 390 where my GTX 750ti LP once lived but as I now spend more time with my laptop on the sofa the Dell optiplex is now a donor for my gaming laptop build. I'm using the Dell motherboard for this build. It has a i5-2400 CPU - 8GB DDR3 RAM - MSI GTX 750ti LP GPU. The Dell PSU is too big for this build so I will be using a Seasonic SS-250SU 250W PSU. The laptop used for this build is a Fujitsu LifeBook AH530 that has a 1366x768 LED screen, this screen will be replaced with a higher resolution 1600x900 screen. The extended base of the laptop is now 6.5 cm.
         
        Parts needed to complete the build:
        Seasonic SS-250SU 250W PSU
        PCI Express 16x Flexible Extension cable
        LP156WD1 (TL)(B1) 15.6" LED 1600x900 screen
        LCD Controller Board
        Ultra slim keyboard with touchpad
         
        Work so far in pictures:
         
           








         
         
        Continue reading the full thread here: 
         
      • By moxy010
        setup i have:asus x54c,Nvida geforce gtx660,psu corsair cx600, dock i use: exp gdc v8.4d  note:(originally the notebook had intel celeron b815 processor, i replaced it with pentium b970,and added 2gb of ram other than that no other hardware changes were made) first time i connected it all and powered on,gpu fans started spinnig very fast and screen was on but all black and nothing happened so i tried the delay switch but with the same result, then i connected external monitor to the gpu, finally i was able to see manufacturer logo,but then it hanged on windows loading screen(back then i had windows 7 so you could clearly see the windows logo animation stopped) so i tried to hotplug the egpu by booting with original wifi card in (mpcie) sleeping then plugging the egpu in and resuming,but always i did so i was greeted with instant crash  so i went searching  for answers on the internet and i learned that i should isolate pin 22 so i did, finally i was able to boot into windows (with delay set on maximum) but the card wasnt detected, i purchased setup 1.35,installed windows 10 bios (i had windows 7 uefi)  but i couldn´t get it recognized even in there.  im sure all the componnents are fine, i got it sucesfully runing on my older laptop (lenovo u350) thanks for all the help in advance 
    ×

    Important Information

    By using this site, you agree to our Terms of Use.