With the watercooling the highest GPU load temperature I've seen is 53c.

Compared to a good watercooling setup which would be 3-5c above ambient temperatures that seems quite high.

It's nothing compared to the stock cooler though.

With the stock cooling my 8800GTS would reach 80c under load very easily.

The fan settings for the 8800GTS per Rivatuner are:

Duty Cycle Min 25%
Duty Cycle Max 100%
T Min 72c
T Range 32C
T Operating 82c
T Low Limit 72c
T High Limit 92c

What that seems to mean in practice is that the graphics card fan stays at 60% speed until the card reaches 82c (You can see that in a few of the rivatuner temperature pics on the first page of the thread). After that it starts to ramp up.

3D Mark 2006 Stress Testing
You've probably seen the SPCR Aerocase Condor review where they discuss loading graphics cards using synthetic benchmarks? In particular where looping 3D Mark 2005 (as seen in the Madshrimps review) isn't sufficent to get the card fully loaded.

http://www.silentpcreview.com/article650-page5.html

Room temperature today is 24c approx.

First of all I left the card looping the full 3D Mark 2006 test for an hour. (all default settings 1280x1024 no AA)

At the end of the hour the GPU temperature had risen to 51c.

This was only for about 50% of the time however. Whilst doing the CPU benchmarks the GPU temperature fell to 47c.

After leaving it to cool back down for a few hours I then left it looping the first 3D Mark 2006 Shader Model 3 benchmark (the airship and giant sea dragon one) for an hour. This is at default 1280x1024 no AA.

After roughly 45 minutes of looping the SM 3.0 benchmark the GPU temperature had reached 53c. It then stayed at that level for the next 15 minutes (11 run throughs) until I stopped the test.

Room temperature had increased from 24c to 24.4c (using a digital thermometer). As I'm writing this the room temperature is gradually increasing as the reservoir cools (room temp is 24.6c 30min after stopping the benchmark, the GPU temperature has dropped to 44c)

The temperature of the silver aluminium reservoir felt quite warm to the touch at the end of the test. It wasn't hot enough to burn you but you wouldn't want to keep your hand next to it for a long time either. The black vanes weren't as hot.

I didn't have anything to test the water temperatures with unfortunately. I suspect it was quite hot though.

You really wouldn't want to put too many hot components in one water loop using this.

Have a look at these two reviews where they use the reserator 2 with multiple components:

http://www.xbitlabs.com/articles/cooler ... html#sect0

http://www.pcper.com/article.php?aid=34 ... pert&pid=9

For cooling a single graphics card it seems to be good enough though.

There was also a noticeable "ticking" noise coming from the reserator however. Now that it's cooled down a bit this has stopped again.

It's difficult to describe the noise: think hot metal expanding perhaps.

If you want me to upload the rivatuner temperature monitoring logs of the two tests let me know as they're only 640kb each in size.

I had a go at trying some different clock speeds for the graphics card.

The lowest 2D clock speed my A3 revision card is able to run at is 100mhz core.

If you change the values to lower than this (I tried 50mhz and also 75mhz) the card is unable to display the Windows desktop.

I changed the 3d clock speeds to 612mhz core/1500mhz shader/1000mhz memory on my card.

The A3 revision 8800GTS card seems completely stable at these speeds.

After 2 hours of Test Drive Unlimited the GPU temperature had risen to 56c.

It took 1 hour to reach that GPU temperature and it then stayed constant at that level for the second hour.

Despite being hotter the temperatures do seem to be being controlled by the water cooling.

I'd imagine that's the sort of temperatures you'd be looking at with a 8800GTX card also.

Thanks a lot for taking the time to do the tests and post them!

To me, watercooling a CPU is "just expensive" as there are very good aircooled heatsinks, and thermal dissipation of CPU's today is not that high (my current, old, CPU puts out 80W and the heatsink is cooled using a 100 mm fan - new CPU's have a lower TDP and can be cooled using 120 mm fans).

Video cards however... A high end card will dissipate over 100W easily.

Best way to cool both seems to be aircooling the CPU and watercool the GPU.
It seems tempting to watercool the CPU as well, once you watercool the card. But as in your test, the watertemp reaches a relatively high temperature, which is still great for a card, but a CPU needs a far lower temp.

You convinced me it's possible to aircool a low dissipating CPU (at lower temps) and watercool a high dissipating video card (at higher temps) - one doesn't influence the other (as much), case temp will be lower then when using a HR-03 Plus, keeping the air for the CPU cooler as well.

No one will complain with a 60 °C at load, without a fan ramping up!

With the faster clock speeds the card is a lot hotter.

At the same time the extra speed is worthwhile with a 3D Mark 2006 Score of 10,800 approx for my card.

This article shows the performance scaling from different clock speeds:

http://www.madshrimps.be/?action=gethow ... howtoID=72


The 2D/3D Clock Speeds of my GF8800GTS 640mb card

This is one of the newer A3 revision cards with non standard clock speeds. The 2D settings should be fine for any 8800 GTS card but don't use these 3D speeds unless you're sure that your particular card can handle them!

The stock 3D clock speeds for a 8800GTS 640mb card are: (Core 513mhz, Shader 1188, Memory 792mhz).

At a room temperature of 24.5c the Intel Core 2 Duo E6700 CPU (clocked at 6*300 1.8ghz using Intel Speedstep EIST) idles at 40c (temperature measured using Core Temp). The single low airflow fan is sufficient to keep everything running happily.

Idle CPU Temperature at a Room Temperature of 24.5c

When the CPU is needed it runs at (10*300, 3ghz).

Under artificial 100% load on both cores (using Intel TAT tool) the CPU goes up to 68-69c but stays at that level fairly consistently.

In normal use (gaming etc) it generally only gets up to 60c or so.

Because the PC relies on passive cooling so much it's very sensitive to ambient temperature changes. During the winter it will be significantly cooler with recorded temperatures 10-15c lower than currently.

On hot days the temperatures will rise also. For particularly hot summer months I turn the Nesteq PSU fan on manually to give some additional cooling for the PC.

thanks to the WR304

shaved 10 degrees off my 8800 gts temps and 2 degrees off my cpu temp with the underclock feature of rivatuner.

the 8800 gts is heating the case more than my previous x800 so nice to be able to have the same previous noise levels with the underclock enabled

regarding this ducting, I am assuming you have removed the pci slats so that the hot air is ducted out of the case?

I'm glad to see your settings posted here. I have an E6700 and a 640MB 8800GTS too.

My core temps run at around 40-41 too. They will get to around 70 when pushed with Orthos but they don't seem to get that hot while running games. I haven't tested it out too much yet.

Can your card run with a clock speed lower than 100mhz?

Rivatuner shows a low speed of 80mhz but it didn't work for me.

I just tried the lowest rivatuner settings on my card and the whole screen turned into a flickering mess in the same way as at lower clock speeds.

I had to reset the PC to get the screen back.

Rivatuner Software Download:

http://www.guru3d.com/index.php?page=rivatuner


Underclocking Your Graphics Card in Software (No BIOS Flash Needed)

The PCI blanking slots were removed for the duct.

I was a bit restricted as two of the PCI slots were filled. Ideally you'd have the duct stretching to cover all the PCI slots.

Some people also attach a fan to the duct for higher airflow.

Have a look at these pics of other ways of trying to improve the stock cooling too.

http://www.hardforum.com/showthread.php?t=1183118

@dentaku:

You shouldn't have any issues with cooling in an Antec P182 case.

It's only really when you start looking at smaller cases with poor airflow that a Geforce 8800 card could start causing major heat problems.

275mhz on my BFG OC 8800 GTS - it is presently idling at 58 degrees, gone a bit cooler here in the UK presently

this is in a sonata 1 with acoustipack lining, so I think that is pretty good, seeing as my x800 idled at 48 degrees

thanks for the link

You can quite happily run a 8800GTS card at 100mhz core for 2D mode.

There isn't any noticeable performance drop at all.

58c at idle still sounds a little high. That was around the starting point for my card. How high is room temperature? Have you reseated the core with better thermal paste?

Something else I think would work well is to swap the double PCI mounting plate of the card for one from a single slot card.

Another alternative would be to cut the blanking plate in half to stop it restricting airflow.

The actual PCI plate comes off easily (Just unscrew the 4 standoffs by the DVI outputs and the single screw in the card).

I had a go with another 8800 card today: It was a Leadtek 8800GTS 640mb card with a custom shroud:

The actual cooler and fan underneath looked identical to the stock cooler.


Leadtek 8800GTS shroud (top) Compared to Standard Nvidia cooler

It was being fitted in a new PC so I only had it for a few hours. I couldn't compare noise to the stock cooler as any noise from the card was drowned out by the CPU and case fans of the PC.

Although it was a brand new card it was a revision A2 card compared to my revision A3 card.

When installed in a PC running Windows XP Pro it seemed to be having some difficulty switching between 2D and 3D clocks though.

This might be because it's an older card revision or just that different software was installed on the PC?

Temperature comparisons were largely subjective but it seemed to be running cooler than my 8800GTS with the stock cooler shroud had.

With the side removed from the case it idled at 44c!

Load temperatures looked to be 69c or so.

With the case side fitted it idled at 50c using the stock thermal paste.

There didn't seem much point taking it apart to reseat the core as the cooler was working ok straight away.

Flashing the BIOS simply to change the clocks for 2D seems excessive when you can simply run a program like RivaTuner or ATiTool that will do it for you and you can keep changing it anytime you want.

Well my card for one won't go that low I'm afraid...

It might be a case of needing to change the BIOS default speeds before rivatuner can set those speeds though.

Obviously, there's some risk reflashing the card but it seems fairly minimal.

If you look at my rivatuner pic a few posts back the 2D mode clock shows a minimum of 80mhz and a maximum of 150mhz.

Using Nibitor and NVFlash I'm fairly sure your card is physically capable of running at least as slow as 100mhz core/400mhz shader/ 400mhz memory.

Both GF8800GTS cards I've tried have worked with those 2D clockspeeds.

Dropping the core all the way to 100mhz rather than 200mhz+ appears to make a significant difference to idle temperatures.

So long as you leave the bootup clocks as standard you can just roll back to the original BIOS if the clocks are too low.

What I've been doing is to save a copy of the original graphics card BIOS .rom alongside the new clocks BIOS on a floppy disk.

If it can't load the Windows desktop you just put a working BIOS straight back on by reflashing the card from DOS.

My impression is that you're only likely to run into problems when flashing the card with a different cards BIOS. For example flashing an 8800GTX card with an 8800 Ultra bios.

There doesn't seem to be any issue when using the original BIOS just with different clock speeds entered.

If anyone here has a kill-a-watt meter, I'd be very interested in seeing power consumption figures for a system with a heavily underclocked 8800GTS, at idle (underclocked GPU) and load (stock GPU clock speeds). Extra brownie points for power consumption at idle with stock GPU speeds, but I understand if you don't want to reflash your BIOS.

Why do I ask? I'm resisting the temptation to buy an 8800GTS because I simply refuse to buy a card that eats 55W+ at idle. But if it draws significantly less when underclocked, that could push me over the edge. Otherwise I'm hoping that ATI's upcoming 2950 cards using the 65nm process will be more efficient. But perhaps I hope in vain ...

BTW, has anyone tried undervolting an 8800GTS?

Stock 2D speeds (513 core, 802 memory), idle: 125W
Underclocked to 260MHz 2D, idle: 117W
Core @ 260, memory @ 400, idle: 115W
1 x Prime95, graphics card idle: 164W
2 x Prime95, graphics card idle: 178W
Stock GPU speeds, 1x RTHDRIBL: 204W
Stock GPU speeds, 1x RTHDRIBL + 1 x Prime95: 228W

8800GTS, X2 4800+ Brisbane (65W), 1 hard-drive, ... and not much else. PSU is a Corsair 520HX. Power measurements are at the wall.

So I'm guessing if I could underclock down to 100MHz in 2D I'd be saving maybe another 8-10W, tops.

Thanks a lot nutball for sharing that info! This begs the question (once again):

Since underclocking doesn't help power consumption very much, has anyone tried undervolting the 8800GTS?

There's a thread about undervolting the 8800GTS cards through the BIOS here:

It seems the card doesn't accept the changed entries though.

http://www.mvktech.net/component/option ... /catid,13/

You could possibly try hardware undervolting the card perhaps? It's shown to work for overvolting the card so perhaps would work in reverse.

http://www.madshrimps.be/?action=gethow ... howtoID=72

I won't be trying it though.

What the reviews don't really mention is that it's quite possible to reduce a GF8800GTS 640mb card to slideshow speeds, even at a resolution of 1280x1024.

You need all the performance you can get out of it.


3D Mark 2006 score for my PC with 8800GTS card (Core 648mhz/Shader 1620mhz/Memory 1000mhz)

For comparison my brother's PC (identical to this one apart from having a 7900GTX card rather than the 8800GTS) gets 6281 in 3D Mark 2006 at the same settings as above.

In the Lost Planet DirectX 9 demo benchmark (1280x960, most settings on high but no AA and 4x AF) my PC gets an average framerate of

Snow 57
Cave 64

The PC with a 7900GTX gets an average framerate of:

Snow 26
Cave 41


Lost Planet DX9 Demo Benchmark score for my PC with 8800GTS card (Core 648mhz/Shader 1620mhz/Memory 1000mhz)

If you force 16x anisotropic filtering and also 8x anti-aliasing or higher on a 8800GTS 640mb most games become largely unplayable.

It's quite possibly more of a driver problem than anything else but is a real issue. (Windows XP Pro, 158.22 driver)

On Rainbow Six: Vegas for example 1280x1024 resolution, high detail and forced AA/ AF results in a framerate as low as 11 frames per second.

On Colin McRae Dirt some of the circuit races are almost unplayable (that's without AA/AF forced). The Circuit des ducs for example is just a stuttering nightmare at 1280x1024 and a mixture of medium/low graphics settings.

The rest of the game runs ok at 70fps+ though.


Circuit des ducs Colin McRae Dirt

Looking forward to doing some tests, while being a bit cautious as well...

I just ordered a reserator 2

Make sure you flush the reserator 2 and waterblock through with de-ionised water before using it. The inside of the reservoir didn't look that clean on mine (residue from manufacturing I think).

I'd also recommend getting proper hose clips for the tubing rather than using the included zalman clips.

Thanks. I also saw an easy mod here (needs the coolant to be drained first).
Someone else tried it out and posted later in the same thread, "temps under load dropped about 5 °C" (not specific on what temps exactly).

That would probably work quite well.

The bottom half of the silver reservoir gets noticeably hotter than the top section.

I'm not sure if there's a pre-installed connector in the reserator 2 though.

It's not very clear from this pic.

http://www.xbitlabs.com/misc/picture/?s ... ob.jpg&1=1

How did you get on with the reserator 2?

I had another go at lowering the clock speeds on my 8800GTS card.

Although the core won't go lower than 100mhz the card can display the Windows desktop with the shader speed lowered to 100mhz also.

(Core 100mhz/Shader 100mhz/ memory 400mhz)

At this speed there were noticeably problems with opening and displaying windows. It was taking ages to display new Windows explorer windows and webpages. The whole PC seemed on the verge of locking up.

It seems that you need at least some shader performance for the card to work normally.

I went back to slightly higher settings of (core 100mhz/ shader 300mhz/ memory 400mhz) which seems to be working ok.

At a room temperature of 19.6c the card GPU now idles at 36/37c. (CPU temp idle is 35c per coretemp, Asus P5W DH Deluxe system temp is 37c, Samsung Spinpoint T HDD temp is 37c also (In Growup Japan Smart Drive 2002c enclosure)).

Because it relies on passive cooling so much the entire PC is massively affected by changes in ambient temperature though.


8800GTS 640mb idle temperature (core 100mhz/ shader 300mhz/400mhz) Room Temperature 19.6c

Some other interesting things:

Turning on Speedfan immediately puts the graphics card into 3D mode with the higher clock speeds enabled. I'm not sure why it does this but it happens every time.

Underclocking the graphics card memory for 2D mode with rivatuner forces the memory to stay at that low level in 3D mode too.

It seems that the Windows Vista aero interface forces the card to stay in 3D mode all the time so underclocking in this way may not work. Disabling aero may let the card drop to 2D speeds though. (I use Windows XP so can't check that).

Received the reserator in good order a few days back, checked all items and it's complete (bought second hand on Ebay).

Almost a shame not to use the gold plated CPU waterblock...

I don't have the other items I ordered, so I will have to wait until all items are in...

Is there a hose connector in the base of the reservoir with the reserator 2?

I don't really want to drain mine to check.

There is no hose connector like the blue one on the reserator 1...

The water pump covers the intake hole, and is held in place by a bracket with two screws (very hard to reach).

The other (outlet) hole is sunk into the base and is not covered with anything you can mount a pipe to.

A possible solution might be to place some sort of bulkhead between the pump and the outlet hole.
A somewhat rigid rubber mat might be placed in the cilindrical reservoir, large enough to just fit around the pump, and maybe 1/2 or 2/3 the height of it:



I don't know how to make sure the rubber mat won't lift a bit and make warm water come into the compartment of the cool returning water, maybe some spring from the top reservoir seal might prevent this.

Anyway, the placement of the pump, and the cilindrical form of the reservoir should make for a snug fit for the rubber mat on the base (with increasing mat width, the radius would decrease so it will not cover the outlet hole) and maybe the friction of the rubber mat itself will prevent it from moving upwards.

One advantage: you will not have to drain the system this way, just placing/wedging the mat inbetween should be good enough...

I am using ATI tool 0.26 under XP to have my bfg 8800gts 640mb OC run at 100/200 (400 effective) when not in a game/3d app and I have a couple of questions.
1, does this underclocking also reduce the shader clock?
2, can any harm come to the card from changing clock speeds all the time?

The chart on this page shows how the linked shader speed scales upwards when the GPU core speed is increased.

http://www.madshrimps.be/?action=gethow ... howtoID=72


GF8800 Clock/Shader Link Taken From Madshrimps.be Overclocking Guide

Underclocking the card GPU core should reduce the shader clock also as they're linked together normally.

The only way to have unlinked GPU core/ shader speeds seems to be by changing them through the BIOS.

If you load up Rivatuner the hardware monitoring will show what speed the graphics card shaders are running at. They're probably at 240mhz or so I'd guess.

http://www.guru3d.com/index.php?page=rivatuner

I'd check to make sure that the memory speeds are returning to full speed in 3D mode also.

Varying 2D/3D mode clock speeds is nothing new.

All (not too sure about that?) Geforce 7 cards do this as standard anyway. For example a Nvidia GF7900GTX card drops to 275mhz core/275mhz shader/275mhz memory by default in 2D mode.

It's just that Nvidia disabled this feature with the Geforce 8 cards for some reason.

In terms of damaging the card it's more likely to be the other way round. Putting the clock speeds down for normal use will put less stress on it and allow the components to run cooler.

OK I downloaded rivatuner and checkd, and the shaders do reduce as well, also the memory changes speed as it should. Unfortunately 3D detection dosent work with every game but i just use a hotkey to force it if needed. With these settings I idle at 55C, does that sound ok?

Geforce 8800 idle temperatures seem to vary a lot between cards.

How hot is your room? You can't safely compare temperatures between cards unless you know what the ambient temperatures are.

At a room temperature of 20c approx my 8800GTS 640mb card idled at about 52c approx using the stock cooler (details on the first page of this thread).

Did you reseat the graphics card cooler?

It's well worth doing that as the default thermal paste on the 8800 series cooler is often too thick.

Reseating with Arctic Silver 5 dropped my GPU temperatures several degrees when using the stock cooler.

Have you taken any PCI blanking plates out beneath the card? Doing that and building a cardboard duct should help reduce heat buildup in your case.