I'm afraid I'm not terribly technical, but there is nothing wrong with my hearing and I have a situation here that makes no sense to me.

About a year or so ago I wanted to buy a new computer and wanted it to be quiet, so I snooped around and a lot of people were recommending the Antec Sonata so I bought that, with an Asus P4P800S mb. Right from the begnning I was a bit disappointed because it didn't seem more quiet than my old Gateway. When I called the tech explained that the new machine was a lot more powerful than my old one, and consequently hotter, so I couldn't really expect it to be quieter. I let it be, because the machine ran great.

This week I was setting up a new Dell Demension 1100, which is also a Celeron chip, and I was stunned to find that this box is truly quiet. I estimate it would take 5-8 of these Dells to equal the noise from my Antec. How the heck can this cheap Dell box be running rings around my specially designed quiet Antec?

FYI, I have determined that the Antec's chasis fan is indeed very quiet, it's the one for the MB that is producing 90% of the noise. According to the ASUS PC Probe utility this fan is running at around 2500 rpm with the CPU at 125F. Do these figures sound about right?

I look forward to your comments.

The Sonata does provide a good starting-off point for a quiet PC, but as you've found out, a reasonably quiet case doesn't mean a whole lot if the rest of your components aren't quiet. Dell uses motherboards with passive cooling (no fan on the chipset) and they use quiet cooling solutions on their processors, and unless you go for an enthusiast level PC, they tend to use fanless video cards or a built-in GPU as well.

If you want to acheive a lower noise level, you'll have to look at quieter cooling solutions for your components, just like Dell does. I'd say start off with the motherboard fan (chipset fan) and the processor (CPU) fan. You may be able to put just a heatsink on your chipset if you get a good one (like Zalman NB47J), or you could get a quieter solution with a fan (such as the VANTEC CCB-A1C Ball VGA Cooler Kit, which I use). For the CPU fan, something like a Zalman 7000AL-CU should be sufficient and quiet (again, I use this). Video card fans can also be a source of noise, so if you have a fan on your video card, you can get something like an Arctic Cooling Silencer designed for your video card. Everything I mentioned is available all over the internet (and I know it's all available specifically on newegg.com).

Of course, once you take out those components, you might be surprised how loud your exhaust fan and PSU fan actually sound I ended up replacing the exhaust fan on my Antec case with a Nexus Real Quiet Case Fan.

I hope this helps!
-Douglas

Welcome to SPCR!

As was mentioned, the case only holds the components and allows for air flow -- the active components produce the noise. There are inexpensive, passive northbridge heatsinks (from Zalman) that could make your motherboard silent.

What is the graphics and the CPU heatsink and fans? Does the power supply fan ramp up when you use the computer? You might want to do a search for the Sonata front intake mod -- it will cool the HD down at least. And what type of HD is it?

Along with what has been already said, there is a lot we do not know about your Sonata system. How much noise an unmodified system makes is often proportional to how much heat it creates, and what specific parts and cooling solutions it has.

For instance, the Dell system is probably very minimal, with an integrated graphics processor, and a carefully engineered and integrated cooling method for several components all together (at least, that's what Dell used to do). On the other hand, if your Sonata is running a hot CPU and video card, and has a northbridge cooling fan, that could make things a lot louder. More fans, more heat to evacuate, which in turn makes the fans run faster. Unmodified, all the fans in that system except maybe the rear case fan (set to Low?) would be automatically temperature controlled.

(And welcome to SPCR as well. )

It is quite common for people on this forum to replace the motherboard chipset heatsink/fan with an after market version. Unfortuneately, you ususally have to remove the motherboard to do it. If you do replace it, do not use Artic Silver 5 paste (Cermanique or whatever comes with the after market heatsink is OK).

There are many posts on this forum about replacing the motherboard chipset heatsink/fan.

If it's a Sonata Mk I with the TP-380S PSU, then you'll cut the noise noticeably by switching to something quieter. The change to the S12-430 was one of the top four quieting improvements for me. Others in the top four already mentioned:

- Active to passive chipset cooler (Zalman NB-47J). If your mb uses loops rather then push pins, and you don't want to make your own wire clip, Zalman has just announced the ZM-NBF47 with hooks.
- Active to passive graphics cooler (Aerocool VM-101)
- Stock CPU cooler to Zalman 7000, then to Thermalright XP-120 w/ Papst fan

Other good changes for a Sonata-cased system:
- Improved isolation for the hard drives in the sleds with this method created by m0002a. Cheap and easy if you have access to US-threaded screws.
- Replacing the front panel with same from a Sonata Mk II (better intake air flow; $20 direct from Antec)
- Quieter (Nexus, Yate Loon or Globalwin) 120mm fans for exhaust and intake (latter at lower voltage). The supplied Antec isn't bad, but these are quieter.
- Switch to a quieter HDD (Samsung SP2004C for me) for primary storage

having worked on a couple of Dell machines recently i can say that they are NOT all made to be quiet. the constrained formfactor in some of thier machines creates heat exit problems for P4 based systems. Celerons have a lower TDP though, and that makes a huge difference.

Thanks for all of the responses, great forum. I'll try to add some details regarding your questions.

First of all, I'm a bit confused by the separate references to motherboard fans and CPU fans. When I look inside my box, I only see one fan mounted directly over the CPU socket. It's a Sanyo Denki 109X9912T00536. I don't see that model number in Google, but the fan/heat sink looks very close to this:
http://www.goldmine-elec-products.com/prodinfo.asp?number=G12937

According to ASUS PC probe, the chasis fan and the power supply fan do not ramp up, i.e. they never reach the threshold speed of 600 rpm. You fellows think these are perhaps set to low, so all the load is on the CPU fan? The HD is a Maxtor, I doubt that is an issue because heavy usage has no effect on the CPU fan speed. Ditto the graphics card, which is nothing special.

There have been a number of suggestions for modifications, but if we concentrate on the CPU fan for the moment, as I've verified that is where 90% of the noise is coming from (by temporarily stopping it as suggested in the FAQ) do you reckon that something like the Zalman 7000 would fit my mb? It looks like this:
http://www.asus.com/999/images/products/170/170_l.jpg

Thank you all.

The other posters assumed you had an active cooler on your MB [northbridge chip]. You have a passive chipset cooler on your MB, so you don't need to replace that.

The Zalman 7000 extends 1/2-5/8" beyond the CPU HSF retention frame. If you have that much room to your PSU, then it would fit.

However, a Thermalright XP-90or XP-90C would fit easier, be more effective and quieter with a 92mm SPCR-friendly fan like a Nexus or low/medium-speed Yate Loon. In the direction of interference with your PSU, the Zalman 7000is 108mm wide (just measured one that is sitting here), whereas the XP-90 is only 96mm wide, so there's 6mm (~1/4") more clearance.

I've linked the SPCR reviews.