Dell Optiplex Fan noise levels

AdamG

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Dec 21, 2013
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Hello, Quick question, I am building a PC and since I went intel I am a little short on cash so I am currently on a optiplex at the moment for now just for the next month or so while I prepare to purchase 2500k, cooler and some ram to get up and running; my question is about the dell optiplex, I purchased a p4 560 prescott 3.6 ghz to replace the current cpu, as its old and maxes at 100% in simple games like quake 3, from the late 90s, which didn't make too much sense considering the computer has hardware from 5 years or so later, but anyway I purchased the replacement cpu and thermal grease for it, however I notice the heatsink with the exhaust fan doesn't look like it would fit a newer quieter stock cpu cooler, since this current model uses plastic snaps, one on each side of the heatsink to hold it on the processor with a few plastic clips, is there anyway I can replace this CPU cooler for a quieter one for the next month?

The cpu maxes at 100% and the fan ramps up and never goes back down until reboot, the air coming out the back of the CPU is not even hot as you would expect for modern cpus, its actually cooler then my rooms ambient air but I read on this forum and others that it may be something to do with the motherboards readings on the fans, and just defaulting it to 100% to be safe the cpu is being cooled.

The Heatsink doesn't have any fan on it directly, just copper pipes with metal fins and the exhaust fan on the back of the computer is what pulls heat off the heatsink, I didn't really want to replace with another one as I suspect it will just be the same, any ideas? :s

Pic from internet what this one looks like :
jjnl.jpg


And here is the heatsink that goes up through the green plastic shroud and has air extracted from it by the really loud fan:
12bg.JPG


Small note, I purchased this whole little tower off ebay for 30$ so I couldn't really care about the condition or what not, it works fine for everyday tasks as long as you can handle the sound it makes. The cpu heatsink was completely covered in about 1/5th inch of just cooked on lint type stuff, I got as much of it off as I could when I heard how loud it was at start up when it first got here, but as you can see some of its still caked in the fins, and the plastic shroud/fan has like almost a resin or just sticky from plastic melting I suppose, it looked like the cpu shroud had never been moved and the heatsink never cleaned in 10 years when I got it, needless to say cleaning it didn't really help much, the fan is a little different sounding now that I got alot of gunk outta it, but its still pretty sticky all over it, and the heatsink is aswell on the metal fins.

I already have the $6 "new" 560 prescott p4 on the way, hoping that will remove the 100% taxing on average tasks like 720p video watching, or playing a older 1999s game, but no big worries; I recently purchased a 650 Ti and I am frankly already aware there is not much of a point of installing it as the cpu setup on this older dell is quiet bottlenecked for anything relative to using a dedicated GPU. I measured the PCI 3.0 on the new asrock mboard laying in wait compared to this foxconn dell one, and it seems to be the same and I've read its backwards compatible just matter of dimensions and fitting, but we will see how the 560 prescott works out compared to the 520 in terms of performance before I even bother trying to fit it.

Any suggestions on how I could get a adequate cooler/heatsink setup for this p4 without drowning out anything else in the room, I couldn't imagine a work place using these for if there was more then 2 of these in one room you would have hard time hearing anyone talking next to you :#

Some threads I've read suggest its a CPU related problem, and stays with CPU after its switched out, some suggest its motherboard design with the fans not giving reading appropriately, I figured I'd see what people here could conjure up while I'm waiting for usps/ups deliveries.

Won't be finishing new rig for another month atleast so would love to get a quieter setup for this older dell, and then can just toss it in the living room for computer illiterate people to use for mediocre web browsing and email when I'm finished building intel setup.


 
Solution
Here's a Bitfenix "Specter pro" fan I picked up. Part Number BFF-SPRO-12025KK-RP. It came with a toggle switch to throttle it down to 50%. Smaller aftermarket fans like this (there are hundreds take your pick) don't usually spin up as fast as something like the one made for the CPU cooler. So even at 100%, which is only 1200RPM the noise is rated to only 18.9 dB. Pretty quiet. I'm not sure you can change the cpu cooler because that is a Dell motherboard and the holes (for the supports) may not line up. The 500w PSU (raidmax) will be better than stock but no guarantees about it working as lower quality PSU rated to 500W usually give less, in the neighbourhood of 420-430W max (just make sure it has 20 amps on the 12v rail as specified by...

Dom_79

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The "resin/melted plastic" on the heat sink is tobacco resin. I've seen that quite a few times cleaning the rigs of family members that smoke (to excess)while on the computer. Make sure you have some thermal paste when reseating that heatsink. You could always grab a 120/140 mm fan with a small noise profile (24db or less), plug it directly into a free molex (I see in your picture that you have one) from the psu and use a glue gun (hot melt glue) to secure the fan to the inner case in front of or behind the heatsink. The current fan running @ 100% all the time sounds very much like incorrect temp reading by the mobo. Not much to do there. Compressed air EVERYTHING out of that case (cans of that stuff are cheap). "Rubbing-alcohol" (isopropyl alcohol) on a q-tip will clean all the smoke off that heatsink BTW.

Just my two cents but don't waste your time installing the 650 Ti in there. If you're only using that rig to play old 90's games (I'm still a fan of Wolfenstein3d-original and Civ 1) that card is completely unnecessary. The on-board should be fine. If you're dead set on it though you can use it if you upgrade the PSU to at least 500W (you need the power -20amps on 12v rail I believe and a "6prong" PCIE power connector that your stock PSU probably doesn't have) . The PCIE slot is the exact same whether it be 1.0 or 3.0. The difference is in the data controllers, and they are backwards compliant.

Good luck with your temporary rig!

EDIT: OOPS! Just noticed that case is not a minitower but a desktop/small form factor. You will need a low profile card if you want to be able to close the lid. I don't think there are any low profile GTX650 Ti sooo... Cheers!
 

AdamG

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Dec 21, 2013
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It will fit full form factor cards as I measured it against my z75 asrock board sitting waiting for another few weeks for a 2500k and some ram, I had purchased the 650 ti 2gb for that rig not the dell, but I figured since its backwards compatible I would pick up a "new" 3.6 pentium 4 for the dell and try to solve the fan issues, thanks for the hot glue gun tip, I never really thought about that much but just hope it don't come undone anyways, not a big deal as its a older temp pc I bought for around 30-40$ on ebay, I just wanted to get it quiet so when I do get rid of it I can just toss it in the living room for normal use (web browsing ect), at the moment with the current 520 p4 2.8 ghz it maxes at 100% cpu when I try to do any kind of gaming with the onboard, bottlenecking at the CPU I figured, so I decided to order that replacement cpu, some thermal grease.

The 650 Ti was being purchased for this rig:
lm2l.jpg


I have 600w sitting in that, and a spare 500w raidmax (lower quality brand) that I might try to rig up for the dell for the mean time while I'm waiting to pick up a 2500k and some ram for my new intel build. Just playing counter strike is quite taxing on the cpu 100%, and fan is loud as heck so I think with your suggestion of the hot glue gun I can rig up a exhaust fan as suggested, and the only down side to the molex for a cpu cooler connection instead of fan header would be that it would run at 100% potentially wouldn't it? Kind of defeating the purpose of trying to quiet it down, is there a way I can have that throttled? Perhaps a newer heatsink and cooler would be alot quieter at 100% then this dell fan anyway, so I might give it a shot, the TDP on the p4 3.6 ghz prescott replacement CPU for the dell is 115w which exceeds most of the lga 775 coolers I could find tbh, but I think I might beable to work with it anyways, its a old pc nothing really lost if it overheats, the replacement cpu is 9-10 years old since release, and only cost $6, lol. :D

Currently even late 90s games will be interrupted by the cpu being at 100% taxed out, so I had figured it was pointless to install it as the bottleneck was there with anything I was playing, theres some steam games I was interested in playing until I'm finished the other rig so I might still try to fit her if I can work things out but main goal for now is definitely replacing the cooler for a better one, and picking up a exhaust fan to glue to the case perhaps as I think that would work good enough, maybe use a few twist ties to be sure it don't fall in the event the glue did give out, according to the very top of this .pdf file ( ftp://ftp.dell.com/Manuals/all-products/esuprt_desktop/esuprt_optiplex_desktop/optiplex-gx280_user%27s%20guide_en-us.pdf ), its a small mini tower computer that fits full height cards but anyhow not a big deal for that part. 4th computer pic on the list, about the same amount of space as the new case I bought with maybe a inch or two smaller on width, closing the case isn't really a big deal anyhow only temp for now. Tnx for suggestion, let me know what you think about the throttling of the molex connection for the cpu fan.
 

Dom_79

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Here's a Bitfenix "Specter pro" fan I picked up. Part Number BFF-SPRO-12025KK-RP. It came with a toggle switch to throttle it down to 50%. Smaller aftermarket fans like this (there are hundreds take your pick) don't usually spin up as fast as something like the one made for the CPU cooler. So even at 100%, which is only 1200RPM the noise is rated to only 18.9 dB. Pretty quiet. I'm not sure you can change the cpu cooler because that is a Dell motherboard and the holes (for the supports) may not line up. The 500w PSU (raidmax) will be better than stock but no guarantees about it working as lower quality PSU rated to 500W usually give less, in the neighbourhood of 420-430W max (just make sure it has 20 amps on the 12v rail as specified by the card manufacturer). But like you said it's only a temp rig and the only thing you may find annoying is if that PSU is being taxed by the CPU and GPU, in this config probably just over 50% at anything over idle, the fan of the PSU could rev up and be noisy.
My mistake, I thought the case was a smaller form.
BTW I didn't make it clear, but I was suggesting scrapping the stock CPU cooler fan and using an aftermarket on the heatsink. t seems that mobo is not recognizing the proper temp of the CPU so adding an exhaust won't help it spin down (it'll still think it's hotter than it is).
You may want to check in the bios and see if the CPU fan is set to "always full" or something like that. I'm on a Dell now and it has the option to set the fan to max always (can't remember the exact wording) this may solve the issue without any more fiddling than that :)
 
Solution

AdamG

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Dec 21, 2013
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Thanks I will pick one of these specter pro fans for exhaust, Ill check the bios and see if there is a option for the current fan but I think the aftermarket should be good, 22amps on the raidmax and 48amps on the cooler master psu, should work out with the hot glue n twist ties, upgraded cpu and grease is waiting at post office so should be good, gonna order this fan today, probably pick up a couple more for my newer build aswell as it needs one more in front and 2 on top; appreciate the help should be good to go, and at very least will have a bit quieter setup with this older rig to toss in living room in a few weeks for parent/relative to use if they need basic web surfing. Tnx!