Experiences with a Gigabyte 6600GT Silentpipe

Jaer · Post by **Jaer** » Thu Jul 07, 2005 1:50 pm

A couple of weeks ago I started to build a new system and of course I wanted as quiet operation as possible. Being an all-around computer user writing, browsing, editing homepages and playing games from time to time I wanted decent performance as well. I've described what parts I decided to buy and the initial experiences in another thread. I'll try to update that in the near future.

But this post is about my experiences with the Gigabyte 6600GT Silentpipe (nx66t128vp) that I used for this build. Note that what I describe below is only valid for this particular card. Other models with passive cooling from Gigabyte may use a different setup and a different sensor chip.

I don't have access to a digital camera at the moment but there are nice pictures of the card in the review at THG.

front

back

So after putting everything together and installing WinXP, drivers and some applications it was time take a closer look at temperatures. Normally I use Speedfan to monitor temperatures so I started there.
Everything looked ok,

Sensor chip: National LM99
GPU core temp: 42C
GPU board temp: 50C

For comparison I checked the temperature monitoring in the Nvidia display utility. There was no GPU board temperature displayed there but the GPU core temperature was 75C! And this is at idle... Hmm, I needed a third opinion so I started Everest Home Edition. And I surely got a third opinion, 66C. And Everest detected the sensor chip as National LM89. But on the positive side it displayed the same GPU board temperature as Speedfan, 50C.

I decided to see what would happen during load so I started RTHDRIBL (windowed mode, 800x600) and left it running until temperatures were stable, rougly 25 min.

Ahh, a very bad ventilated case, I can hear you think. Well, there is 2x120mm Nexus fans on 12V. One intake in the front and an exhaust in the back. The AMD64 3200+ venice is passively cooled by a Thermaltake Sonic Tower, and landed on 46C during this test (37C at idle). So the ventilation is ok.

So I went back looking at reviews on this card again to see if anyone else had very high temperatures. A few of them stated that the card got very hot but only here did they mention temperatures and from what utility they came from. Using the readings from the Nvidia driver they saw values >100C duing load. In this same review the temperature of the heatsink was measured with an IR thermometer to be 70C.

I started looking closer at the heatsink assembly on the card and it seemed wobbly. There is a thermal pad between the copper plate attached to heat pipe and the GPU. If this got bumped at installation or laying loose in the retail box it might dislodge and not make very good thermal contact anymore. So I decided to take the heatsink off and clean the surfaces with isopropanol before applying some Zalman thermal grease. The whole thing was put back together and this lowered temperatures ~10C.

A note on the heatsink assembly. The copper plate making contact with the GPU has the heatpie attached to it. But the heatsink on that side of the card does NOT come in contact with the heatpie. It only makes two small contacts (20x8 mm approx.) with the copper plate on each side of the heat pipe. I will take pictures of this when I get hold of a camera again.

A step forward but I was still not comfortable with the temperatures. So in search for the reason for the differences in displayed temperatures I read on the forum for Everest and in the information about Rivatuner that driver display temperatures are temperature compensated and that the level of compensation might change between driver versions even. Why this is I have no idea.

There seems to be very little difference between the two different sensor chips detected, LM89 and LM99. One can note though that the absolute maximum working temperature for the diode in LM89 is 125C, interesting with a throttling temperature of 145C in the driver. But it seems that the chip on the Gigabyte card is the LM99, there is an 8-pin chip of the right size marked T17C indicating this (according to the link above). The datasheet also indicates to the origin of the low values reported by Speedfan. The sensor has a builtin offset of 16C that Speedfan does not seem to compensate for. That is,

Tdiode = Treported + 16

This can be checked also with Rivatuner that can read the temperature from both the Nvidia driver and directly from the sensor chip (this value is identical to the one reported in Speedfan). Everest on the other hand also claim to read the sensor but always display a value about 10C below the Nvidia driver utility so it seems to compensate for the sensor chip offset. The difference between sensor chip output and the reported value from Everest is somewhat higher than 16C though.

So where does this leave me? I bought a Zalman VF700-cu and replaced the passive solution. Below is a comparison at the two cooling solutions during different settings.

All numbers are idle/load. Load is from running RTHDRIBL (windowed mode, 800x600) until temperatures were stable (*the load test for Zalman, passive was stopped after 6 min. Guess you can't run it passive with load

). Note that for idle the Zalman VF700-Cu without the fan actually performs as well as the stock heatsink.

You can judge for yourself if you think the passive solution from Gigabyte is adequate. Even though I had no graphical artifacts at a core temperature above 100C or stability problems I do know that I don't want a >70C heatsink or a >100C core. Actually seeing the board hitting almost 70C made me more uncomfortably than the core at 110C. Even though the GPU seems to be made to withstand this there are a lot of standard components around it that is not. But this is my personal view.

And if you have a Gigabyte 6600GT Silentpipe, could you please reply with your temperatures and from which monitor program they have been obtained.

/Jaer

Don't know why my posts always end up so long...

I hope there is someone that manages to stay awake to the end.

Aleksi · Post by **Aleksi** » Thu Jul 07, 2005 8:13 pm

Hi Jaer,

thanks for the post, I was looking for similar information recently.

I ordered myself the Gigabyte's passive 6800 and I'm having temperatures of the core 80C while idle and 100C when under load. I've also tried having a Nexus blowing at the damn thing at full but without any help.

It's funny that the heatsink on this thing however gets burning hot, so it is making contact. Maybe the implementation just isn't the best possible

Tetra · Post by **Tetra** » Thu Jul 07, 2005 9:42 pm

I'm actually returning the two of them I own for a similar reason. I've been unable to keep the tempatures under 120c under load, regardless of the airflow over them. 120mm Nexus wasn't enough, and neither was a rather loud, unlabeled 120mm fan I had sitting around that had to push at least 60cfm. Great looking card, both in applications and physically, but not well executed.

EDIT: Temps taken from Nvidia control panel, while running RTHDRIBL

Twigathy · Post by **Twigathy** » Fri Jul 08, 2005 1:19 am

Well, I was about to order myself one of these (The 6600GT Silentpipe)...but now....

Is the card stable? Did you have problems with it crashing, or any graphical corruption? If not then I say "Why Worry?".

Jaer · Post by **Jaer** » Fri Jul 08, 2005 5:25 am

The often stated "a hot heatsink is a working heatsink" is somewhat flawed. The point of a heatsink is to lower the equilibrium temperature where as much heat as is produced by the heatsource (here GPU) is dissipated to the surroundings. The worse the heatsink, the warmer it has to get before it can dissipate the heat absorded from the heatsource.
An efficient heatsink does not have to become very hot to do this and therefore keeps the heatsource at a lower temperature. The heatsource is of course always warmer than the heatsink. How much warmer depends on the effiency of the heat transfer between them. So a 30C diffence between the GPU and the heatsink is not very good.

Twigathy: In the end of my post I clearly say that there was no instability or graphical corruption during the testing. I have only had the card at these temperatures for short periods during testing.
I also say that you have to decide for yourself if the cooling is sufficient or not. My personal opinion is pretty clear, but I'm not saying "Stop buying this card!". But I do think it is good if people know what they get before making up their mind.

/Jaer

Twigathy · Post by **Twigathy** » Fri Jul 08, 2005 5:32 am

Okay, thanks for the clarification

.

Aleksi · Post by **Aleksi** » Fri Jul 08, 2005 5:41 am

I have a Zalman D-series VGA heatsink installed in my old card. I would most likely install it on this one, but haven't found a 100% confirmation on the socket orientation and on the fact, that would it fit that card? Everywhere I look it seems people have either modded different models or reported of problems installing a custom cooler

Techno Pride · Post by **Techno Pride** » Fri Jul 08, 2005 7:17 am

Aleksi:

the passive Zalman works fine on the PCI-E version

on the AGP card with the GPU slanted @ 45 degrees, it is also possible to install the zalman with some modifications.

Aleksi · Post by **Aleksi** » Fri Jul 08, 2005 8:19 am

Hi Techno Pride,

I read your post on the 6600 / Zalman swap. I guess I'll just have to take the thing apart and try it out. Really disappointing though to buy a passive card which has a bad implementation of the passive cooling.

Techno Pride · Post by **Techno Pride** » Fri Jul 08, 2005 8:53 am

is your card the AGP6800?

then you probably do not need to do any modifications. The GPU is mounted the right way.

Aleksi · Post by **Aleksi** » Fri Jul 08, 2005 9:02 am

Hi,

yes, it's the AGP version of the fanless Gigabyte 6800 (GV-N68128DH). Thank you for the info... I guess I'll have to take it apart and swap it.

I must say it's a pity, as the card seemed to have so much potential. Maybe just reinstalling the heatsink with some proper silver paste could help. Although, if it's off, why not swap it for a proven solution.

The main problem for me is the 100C core, simply don't think it's acceptable.

Techno Pride · Post by **Techno Pride** » Fri Jul 08, 2005 9:13 am

probably a bad mount by the worker at Gigabyte's factory.

I was getting 90+C load temps on my 6600 before. Had to redo the Zalman a few times before temps became acceptable.

However, for the premium manufacturers charge for passive cards, you wouldn't expect to receive such a shoddy product from Gigabyte.

scruzbeachbum · Post by **scruzbeachbum** » Fri Jul 08, 2005 9:27 am

I have the Gigabyte 6600GT fanless AGP and am getting:

Idle 3DMark2003 GuildWars 30 sec later*
Chassis 34C 35C 35C 35C
CPU 50-51C 52C 52C 52C
GPU 58-60C 70C 85C 77C

"30 sec later" is where I was playing Guildwars, quit the game and then idled for 30sec.

BrianE · Post by **BrianE** » Fri Jul 08, 2005 9:41 am

There is a forum thread somewhere else that I've seen that actually shows a ZM80D-HP installed on a 6600GT AGP. It looks like it fits, but it sticks out further (a few centimeters from the looks of it) than on a "normal" install. This is because the GPU also sits more in the middle of the card rather than closer to the MB. If you're worried about how much width you have in your case this might cause an issue. I can't remember if he also needed to use an extra set of bracket "wings" to get it to fit....

I'll try and find this stuff later on after work if I can... I tried looking just now but didn't come up with anything.

I'd also like to find out what kind of temps people are getting with this Gigabyte card. Right now, the 6600GT is the only good AGP "upper mid-range" card available, and seeing how passive/aftermarket (passive)coolers are a tricky proposition, I'd like to use one for an upgrade. I'd hope that the stock cooler works well, because you don't save much, if anything, by modding a normal fanned 6600GT.

Too bad Silencers don't seem to fit these either.

Aleksi · Post by **Aleksi** » Fri Jul 08, 2005 9:53 am

I'll try to take it apart tomorrow. Maybe the stock cooler of the Gigabyte couild fit my old Ti4200 (which currently has the Zalman). Probably not, but worth a try!

Techno Pride · Post by **Techno Pride** » Fri Jul 08, 2005 10:02 am

BrianE wrote:There is a forum thread somewhere else that I've seen that actually shows a ZM80D-HP installed on a 6600GT AGP. It looks like it fits, but it sticks out further (a few centimeters from the looks of it) than on a "normal" install. This is because the GPU also sits more in the middle of the card rather than closer to the MB. If you're worried about how much width you have in your case this might cause an issue. I can't remember if he also needed to use an extra set of bracket "wings" to get it to fit....

I'll try and find this stuff later on after work if I can... I tried looking just now but didn't come up with anything.

u mean this?

http://forums.hardwarezone.com/showpost ... stcount=36

Aleksi · Post by **Aleksi** » Fri Jul 08, 2005 10:28 am

That setup does NOT look healthy!

BrianE · Post by **BrianE** » Fri Jul 08, 2005 12:04 pm

Techno Pride wrote: u mean this?

http://forums.hardwarezone.com/showpost ... stcount=36

Haha, I see you're also involved in that thread. Yes that's the one - thanks!

CGameProgrammer · Post by **CGameProgrammer** » Fri Jul 08, 2005 1:31 pm

I found this interesting article comparing various 6600GTs, including the fanless Gigabyte. They read a core temperature of 100 C, yet it was the second fastest card in the lineup.

Anyway I have the fanless Gigabyte but have not yet checked the temperature. I'll do so in a few hours and report results.

I figure, worst-case scenario, I remove the heatsink, clean the thermal compound, add Ceramique, re-attach heatsink. But I'm a newbie regarding these things so I'd rather not do anything complicated.

canceled · Post by **canceled** » Fri Jul 08, 2005 2:32 pm

I have had the passive gigabyte GV-NX66T128VP for a little over a month now with no heat problems at all. I have even overclocked it with temperatures maxing out at 70 celcius, running half life at 1280 x 1120 and also running 3dmark2005 with aa 4x and anistropic 8x. I got the antec 3000 case fan set to low, and a mad dog compusa fan blowing on top of a thermalright xp-90 full blast 1700rpm, and that is all. Maybe those holes in the side of the case give the card some extra cooling air flow, with the mad dog sucking air in from the holes moving air over the top of the card.

I was surprised to find this thread and most people getting temps of 100c!! Yet even these temps are decent as long as no artifacts are present. No need to worry, though I would maybe consider returning the card for a new one if the temps go dramatically over 100c, I have heard of the heatsinks getting bumped around or just the card being manufactured faulty to where temps go overboard. This is not very common though.

I am glad I found this thread because there is little info about this card's overclocking ability, temp range, and stability anywhere. So for the record I have gotten killer speeds out of this card with no added noise or insane temps (on the nvidia site the 6600gt core can take temps up to about 140c but the card will give artifacts way before that, so this core is pretty tough and hard to fry). The card is completely stable for me and the overclock is quite noticable, smoother game play. I could probably overclock it more but I used the coolbits optimal settings finder and just stuck with that.

So for me personally I would recommend this card. The majority of readings on the internet I have done on this passive card's temps have been around the same as mine any where from 40c-80c with the occasional 100c.

Aleksi · Post by **Aleksi** » Fri Jul 08, 2005 2:40 pm

Digging the SPCR forums, found a thread about these Gigabyte 6800 which had a link to nVidia forums. Several users noticed they had their temperatures when they overclocked the card. I tried it and found similar results... Weird!

I'll try to test it further tomorrow and make a chart with rivatuner

BrianE · Post by **BrianE** » Fri Jul 08, 2005 2:46 pm

In my mind, one big

between all the temperatures being reported is how good the airflow is in the case and around the video card. People have fans blowing on or around the card, but where does this hot air go to (if anywhere)? Maybe there is a "hot spot" around that area of the case and too much of the air is just being stirred around and recirculated?

In my imagined usage, I was planning on opening up the two expansion slots above and below the card to let air flow out of the case around it. Maybe some ducting around it too, but I haven't figured much out yet. This would require a fan or positive pressure though..... Anyone doing this already?

CGameProgrammer · Post by **CGameProgrammer** » Fri Jul 08, 2005 2:54 pm

OK, my passive 6600GT idles at a constant 58 C. That's very good for a GPU as far as I'm concerned. That measurement is according to the NVIDIA software's core temperature reading, so it's reliable.

I currently have a 120mm Nexus fan @ 12V mounted on a Zalman FB123 fan mount, positioned such that its axle is next to the 3D card so it blows air along both the top and bottom of the card, parallel to the heatsinks, blowing the air directly at the motherboard. This also has the effect of cooling the nearby northbridge, which also has no fan.

I will undervolt the fan to maybe 9V or so once I get my Fanmate2, but it shouldn't cause a significant rise in temperatures.

I also have the 120mm exhaust fan and my CPU cooler, a Freezer 64, whose fan blows upwards. No front case fan.

I guess the cards kind of need to be "cherry-picked" to get a good one, but it also sounds like the heat problems grow as time goes on, so maybe after a month or so I'll suddenly get worse temperatures. If so, that would almost certainly be due to the thermal compound.

EDIT: Looks like I get the same idle as scruz. I haven't tested it when playing DVDs or games but if I get his max load of 85 C then I'll be satisfied.

scruzbeachbum · Post by **scruzbeachbum** » Fri Jul 08, 2005 6:59 pm

The interesting bit for me was how quickly the temp drops when I go from gaming to idle....8C in about 30 seconds (85 to 77C). My interpretation is that the heatsink is doing it's job and the rest of the equation is how good the airflow is.

Gorsnak · Post by **Gorsnak** » Fri Jul 08, 2005 11:41 pm

My 6600GT Silentpipe idles at 61 and peaks under load at 85. Lots good enough for me.

Shuriken · Post by **Shuriken** » Sat Jul 09, 2005 1:19 am

My Giga 6600GT Passive is idling at 59 C. Not sure what the Load temps are but i haven't seen any problems or artifacts so far.

Aleksi · Post by **Aleksi** » Sat Jul 09, 2005 1:52 am

Hi,

as I said yesterday, I did some testing with overclocking, as it seems to drop the temperatures of the GPU. I haven't found a definitive answer to what is causing the temp drops, most people seem to think raising the GPU clock enables some "hidden" power saving mode.

Below is the chart from my experimenting. I used the T-Balancer to set all fans (PSU, CPU, front intake) at a fixed speed. The front intake fan in my Sonata is in place and blowing at the card at about 600RPM.

To recap, when idling with the 325MHz core the GPU temp was ~77C. When I overclocked the core to 350MHz the GPU temp dropped to 58C!

I'm still considering the possibilty, that GPU temps are somehow affected (causing an error) by the overclocking. Any thoughts?

Aleksi · Post by **Aleksi** » Sat Jul 09, 2005 6:26 am

(sorry for picture quality, had to do them with a crappy camera)

Just removed the original heatsink from the graphics card. It basicly is a very easily detachable/attachable cooling solution at the production line, but it also leaves very much to be desired.

When I removed the heatsink I noticed a few things:
a) the cropper plate connected to the flattened heatpipes was crooked, not lined properly with the core (not a big deal, the card just is crooked on the card)
b) the other side of heatsink was connected to the core element, but without any thermal paste. This pretty much voids the effectiveness of the other side's heatsink. I place some AS5 on the spots I'm talking about.

c) when you look at the heatsink from the end of the card, it is "U" shaped, as you can see in the picture. Apparently they bent this shape a bit to make it more easier to install. So the main core element was a bit like "\" this on the core

also, the mechanics in the heatsink is piece of crap.

I had to exchange all eight screws holding the heatpipe to the heatsink. When unscrewed there was bunch of metal shawing coming off, only two of the screws fitted after this. Found a perfect match with some HDD screws (see picture).

Also, in the assembled picture you can see four screws holding the heatsink in place. These screws go through the PCB to a backplate on the other side. Well, when I assembled the thing back together, I noticed that two of these screws did not unscrew anymore. The bolts on the backplate had started to spin! Don't understand how as they are hexagon shaped, apparently they had risen from the hole just enough...

I guess I won't be taking this apart again. And if I do, I will NOT put the stock cooling solution on it!

Btw, load temperatures dropped from 100C to ~80C, used some artic silver on it, also applied it on those spots that were missing the paste. A bit healthier readings.

BrianE · Post by **BrianE** » Sun Jul 10, 2005 12:48 am

Interesting, thanks for the pictures and posting your results. It sounds like it might not be a bad idea to re-seat the heatsinks on these cards even if brand new.... no thermal paste? Weird.

BTW, what kind of paste did they use where it was present? Looks like plain silicone thermal grease to me, but I might be wrong. Maybe it'd benefit from some AS5 or Ceramique instead.

CGameProgrammer · Post by **CGameProgrammer** » Sun Jul 10, 2005 1:10 am

I just played GTA: San Andreas for a short while at 1680x1050x32, then quit and immediately checked NVIDIA's core temperature readout. It said 70 C. That's very nice, though to be fair I had only played for maybe 20 minutes, possibly slightly less. The computer had been on for over a day before that, so the card was already at its 58 C idle before I loaded the game.

This is with a 120mm Nexus blowing on it at 12V. I'll post more reliable load and idle temperatures once I get my Fanmates and undervolt the fans slightly, since they're the loudest part of my system right now.