Yet Another Ducted Ninja, Overclocked

diver · Post by **diver** » Sun Apr 30, 2006 7:21 am

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This marks my first use of an image hosting service...

The system consists of:

Antec SLK2650-BQE:

As of now the stock exhaust fan is wired for 5 volts. It is rated @ 1600 rpm/12v so I estimate its speed to be 720 rpm. I am considering removing the exhaust grille, but I do not have the tools to do it at the moment.

PSU is the Smart Power 2.0 that came with the case. Since ducting the CPU, the second fan on the PSU runs at low speed during heavy loads and does not contribute appreciably to noise.

The top of the case is lined with 2mm thick vinyl floor tile and the CAG is blocked. The rear tool box has been removed for better air flow. All of the 5.5" bay covers were reemoved to mount the drives. Three werre taped back in place after drilling for improved air flow over the drives.

All other stock openings in the case are open. Thre are no intake fans.

This is a small case and not all that easy to work in.

Cost: $70 including PSU

Abit KN8-SLI:

Mainly chosen for its passive northbridge cooler and low price. $110 at time of purchase and somewhat less now.

AMD 3800+ X2

Stock clock is 2000 Mhz. For the last day or so I have been running at 2599 Mhz, CPU 1.45v, chipset 1.6v, memory 2.7v, and hypertransport +4%v (4X mult).

This OC recipe ran more than 12 hours of prime 95 with two instances going. CPU temp was 49C in a hot 28C room. While running the prime 95 I surfed, viewed streaming video, and did some other disk intesive stuff without problems. It was the streaming video that led to the increase in hypertransport voltage. Right now the machine is running two instances of folding at home. Its 26.5C in the room and the CPU is 48C.

You may see some amazing numbers in overclocking forums, but those guys run prime 95 for 2 hours or super pi 32M without touching anything. That doesn't prove squat.

There is a Ninja Plus under the white cardboard duct. Due to the offset, it was a bit tricky to cut the duct. It would have been much easier with an Asus SLI premium, but I was too cheap to spend the extra $60. The stock Ninja Plus fan (made by Adda) runs @ 730 RPM. The duct made a big difference. CPU temps dropped 2C. The other two sensors dropped by 4C each. The powersupply, which used to go haywire after 1 hour @ 2500 Mhz now runs forever @ 2599 Mhz and does it quietly. If you think your PSU is borked, and it is not possible to duct the PSU, try ducting the CPU. It will do you a world of good, as Pee Wee Herman used to say.

2 Gigs of A-Data DDR400 memory. With the clock @ 260 the memory runs as DDR433 (bios setting DDR333). Stock timing is 3-4-4-8, but this stuff runs @ 2.5-3-3-7 with ease. However, it will not run much faster than DDR433. AT the time this was the cheapest 2 gigs of DDR400 I could find with heatsinks.

Video is provided by a XFX 7600GT maed to a Zalman ZM80D-HP passsive cooler. Idle temperature is dependably room temperature +26C, 52C right now. Maximum observed operating temperature was a momentary 73C running rthdribl demo with the AC off and the room @ 29C! GPU runs @ factory OC'ed 570 Mhz, memory bumped to 765/1530 Mhz.

Under Windows 64 3DMark05 runs around 6350. RMclock is used for power management, Everest for temperature monitoring and other hardware info.

Storage is from a pair of Seagate 160 GB 7200.9 SATA 3.0 drives in raid 0. However unpopular this may be with some members due to concerns about reliability, it really screams on disk intensive tasks like muxing DVD's. The drives are suspended using 1.5 mm Stretch Magic in the 5.5" bays. I chose this method as the material would fit through the small holes in the tool-less drive mounts without drilling. For $2 this was the single largest imporvement in my system. Prior to suspending the drives vibration induced noise was nasty. Threre is a 9 year old floppy in there for the raid bios.

DVD burner is an NEC 3550. It works nicely for burning DVD's but is not especially fast ripping audio, as it does not cache audio. OTOH, it works nicely in the EAC secure mode.

Special thanks to Chris Thomson and JMKE for insipration regarding the benefits of ducting, and many other SPCR members for the solutions they have documented in these forums. If you have never been to Madshrimps, go there now.

IsaacKuo · Post by **IsaacKuo** » Sun Apr 30, 2006 8:33 am

Very nice looks!

So, you've got two fans on that duct? Both a rear case fan and the CPU heatsink fan? I'd suggest trying out removing one or the other. With the Ninja's widely spaced fins, two fans in a push-pull arrangement doesn't move much more air than just one or the other. Probably, it'd be best to get rid of the heatsink fan, and slightly modify the duct to make sure air doesn't bypass the relatively short Ninja above it. (You know, how the stock fan mounting puts a fraction of the fan above the top of the heatsink.)

Do you know how your hard drive temperatures are? So far, I've always avoided putting hard drives in the 5.25" bays over airflow/temperature concerns.

diver · Post by **diver** » Sun Apr 30, 2006 8:48 am

Thanks Isaac

Perhaps I could get away with one fan on the CPU if it was running @ 2000 Mhz. No way @ 2599 Mhz. I estimate the CPU uses 108 watts. Someone tried to go with a single fan and said it had to run 1100 rpm to do the work of two fans @ 700. I tried running the exhaust @ 600 rpm and the Ninja fan @ 650 and it overheated.

For a discussion on push-pull fans see the SPCR review of the Smart Powwer 2.0 PSU.

Hard drives are only slightly warm to the touch. No SMART reading is possible due to the RAID 0. They are passively cooled by the general case air flow.

IsaacKuo · Post by **IsaacKuo** » Sun Apr 30, 2006 9:34 am

The amount by which you can benefit from a push-pull arrangement is extremely dependent upon how restricted the airflow is. The interior of a PSU is highly restrictive--there is never much wasted space. A Ninja is not very restrictive. You can't really deduce what would happen in your system if you don't try.

If you get much more airflow from two fans rather than one, then you probably have a shortage of intake area. A quick and easy fix for this is to open up the PCI slots, which has the added benefit of helping cool the VGA card. Normally, this should be done with care since it may rob airflow from the hard drives, but you already don't have the hard drives next to the front intake.

Hmm...it's a good idea to try removing the PCI backplanes in any case. I can't really tell from the picture definitively, but it sure looks like you've got a shortage of intake area as it is. Also, the video card isn't really within any airflow path to speak of.

Jay_S · Post by **Jay_S** » Sun Apr 30, 2006 9:43 am

diver - I'm jealous of your 7600gt. I bought a 6800GS about a week before the 7600gt & 7900gt were released, and I regret it. The 7600gt benches the same or better (esp. in oblivion) than the 6800gs, is less expensive, and uses less power. Boogers to me.

Questions on your duct: is it 4-sided? Or a 3-sided / [-shaped cross section? I made mine 3-sided for a few reasons, including ease of construction, but also to pull heat away from the voltage regs and stuff. This may be important with your overclocks...

I like the jack knife in the photo - just in case your pc gives you any crap!

Jay

diver · Post by **diver** » Sun Apr 30, 2006 10:20 am

Isaac:

You are right, you don't know until you try. Perhaps, after I finish this folding run. Two of the seven pci slots are uncovered. One has the VGA card. It would not hurt to pull another one right now.

I see what you are saying. Push-pull overcomes impedance. Therefore, the impedance is from the intake.

Jay:

The duct is three sided. Open on the bottom. YMMV. The sensor that Everest calls "motherboard" reads 33C under heavy loads. I think his is the power area. When I had a Zalman 7700 this sensor would go to 41C under load with the room much cooler, and the CPU @ 2400 Mhz. It is kind of hard to predict what will happen, as Iaasic points out.

IsaacKuo · Post by **IsaacKuo** » Sun Apr 30, 2006 10:28 am

Ah, looking at the picture more carefully I see you have those two PCI slots open, right where the VGA heatsinks are. Good thinking!

diver · Post by **diver** » Sun Apr 30, 2006 11:03 am

Iaasic:

You must be drinking some high quality coffee this Sunday AM. I removed another 2 PCI slot covers. Now two are open on each side of the VGA card.

CPU temp looks to be down about 2C. Its hard to tell as it jumps around a bit more now. CPU seems to be around 46 (occasional brief spikes to 47C) while the room temp is 26 with the AC on. PC is running full tilt (2.6 Ghz) with two foldings. Its 30C outside, what we call nice weather around here.

Big news is the North bridge is about 4C cooler. VGA is down by 2C and motherboard sensor looks too be unchanged. PSU fan is running a notch slower as well. There was definitely not enough intake area. Amazing what a tweak will do.

I also nudged the Ninja fan down to 700 RPM from about 720-730. Does not make much difference.

IsaacKuo · Post by **IsaacKuo** » Sun Apr 30, 2006 5:39 pm

Glad to hear you're getting good results from tweaking!

diver · Post by **diver** » Tue May 02, 2006 4:21 am

The tweak goes on...

After devising some new and more difficult stability tests (2X prime 95, mixed, 790 mb each, plus muxing a DVD and viewing an Xvid video all at once) I discovered that the system's virtual memory settings were borked. After fixing that I arrived at a new OC cocktail.

257X10, 2570 Mhz
CPU 1.41 v (1.40 under load)
Memory 2.7 v (DDR428)
Chipset 1.65 v
Hypertransport +4% voltage boost, 4x clock.

A better deal IMO, as a 25.7% OC is achieved at a modest voltage boost. Everest says the voltage range for my CPU is 1.35 to 1.40.

YMMV, but the important thing to remember is you can have the speed and keep it quiet at the same time.