65W: i7 4790s vs i7 4790 underclocked?

[jamesgalb]

I am working on a silent PC right now, and as part of the set-up I am looking for the most powerful 65w processor I can get, to work with passive cooling.

I have read in a couple different places that the I7 4790/S/K models have no manufacturing difference, and that its simply that the more reliable chips get a K rating while the less reliable chips only capable of running at lower power get S ratings... How true is this?

Mainly, I am wondering if I would be better off getting a regular I7-4790, as opposed to an I7-4790S, and underclocking it to be 65w (it would be my frirst attempt at modifying stock settings fyi ).

Is that even possible? Is the 4790 a more reliable chip then a 4790S in any way? Or would I be wasting my time? (Note: I have no intentions of going above 65W for performance reasons, fan-less cooling is important in this build)

Lastly, I am assuming that the 65w i7 Haswell build is my best bet for Power/Heat ratio, but feel free to chime in with any suggestions

 

[NTMBK]

It's not that the S series is less reliable- if anything, it is the opposite. S class (and T class) chips are those which have been found to be able to run at lower voltages than the standard chips. Whereas a standard 4790 may not be capable of being undervolted to hit those power consumption levels.

If you making your buying decisions based on power efficiency, then definitely get the S series chip.

By the way, what are you doing with your 65W chip? If you plan on using the integrated GPU for e.g. gaming, I would recommend getting a 65W Kaveri chip like the A10 7800. If you care more about CPU performance then the Intel part is the way to go.

 

[jamesgalb]

The use will mainly be audio production, with things like Pro-Tools, FL Studio, Abbleton, Etc. Will be running 3 monitors (4 if possible), and doing a fair ammount of multi-tasking.

I dont want it weak at video/graphics stuff just incase it is needed, so I want to pair the CPU with a custom passively cooled 750ti.

Video Card:
http://www.newegg.com/Product/Produc...82E16814487025
Cooler:
http://www.newegg.com/Product/Produc...82E16835186054

If anyone knows of a 750ti with 4 total display outputs that includes a display-port output, let me know. In the mean time, I was going to run 3 displays unless the intel chip would allow me to run a 4th onboard (insight appreciated there).

With the case, I was going to go with a SilverStone raven with inverted motherboard, allowing plenty of heat ventilation through the top, and also does not stack any of the heatin components ontop of each other (CPU, GPU, PSU).

http://www.newegg.com/Product/Produc...82E16811163185

If I found I absolutely needed a case-fan and couldnt run 100% silent, I intend to run a single 180mm fan at the bottom and close off the remaining bottom/side ventilation, in order to create a positive-pressure system of intake and heated air, hopefully pushing enough heat through the top to keep components cool..... Still, ideally the inverted design will allow for enough heat flow through the top already, fingers crossed...

PSU:
http://www.newegg.com/Product/Produc...-169-_-Product

For HD I am going with an SSD and HDD combo... a Corsair MX500 240gb for my OS and all software programs (if I max out I will add another later).

For storage of files and media, I was going to run a WD Red with Intelli Power and a HDD dampener...
http://www.newegg.com/Product/Produc...82E16822236343
with
http://www.frozencpu.com/products/3...D_Noise_Reduction_System.html?tl=g33c113s1182
and
http://www.directron.com/grommet.html

With this setup, I want to toss in 32GB of ram and the new ASUS Essence STX 2, with custom MUSES02 OP AMPs, and begin setting up a Music Studio for the little lady Its in the spare room, with the PC in the same room as all of the recording, hence why I prefer as silent of a design as possible... Room is getting some sound-proofing as well, and wont be at risk of being a warm environment for the PC.

I did have some questions about Thunderbolt support between Z97 and X99... I heard the X99 chipset added better Thunderbolt integration, but I dont see any motherboards in X99 claiming thunderbolt support, while Z97 does (and I want Z97 as I want the less-expensive 1150 chipset)... At the end of the day im wondering if all '9-series' chipsets got the same TB improvements, or if indeed the X99 has better capabilities... All that said, thats likely a question for the motherboard forum.

 

[NTMBK]

Sounds like a good plan- nice to see you have thought through airflow. Plenty of people slap a "passive" cooler on their GPU without thinking about airflow, and then wonder why it overheats. The vertical airflow of that case should work well.

Have you considered putting your mass storage drives in a NAS or small file server? You get the mechanical drives out of your workstation, removing one more source of noise and putting it in a cupboard somewhere, and you will also be able to share your work files between multiple PCs within the home.

 

[jamesgalb]

Sounds like a good plan- nice to see you have thought through airflow. Plenty of people slap a "passive" cooler on their GPU without thinking about airflow, and then wonder why it overheats. The vertical airflow of that case should work well.

Have you considered putting your mass storage drives in a NAS or small file server? You get the mechanical drives out of your workstation, removing one more source of noise and putting it in a cupboard somewhere, and you will also be able to share your work files between multiple PCs within the home.

Yeah the GPU I put some thought into. The 750ti is by far the most capable card effecient enough for a passive cooler, and without a doubt the most current in technologies... I wanted the PALIT 750ti passive cooled card, but I can only find it on ebay from the UK or Isreal, for $200+, and im not even sure about compatibility issues of reviews..

In addition to running the inverted motherboard, I intend to put the GPU midway down the ATX motherboard, putting better spacing between it and the CPU and improving thermal properties that much more Z97 chipset should give my plenty of PCIe lanes for a 750ti in the 2nd or 3rd slot.

I hadnt thought about a seperate storage system... I support it could easily work wirelessly from another room? Id be concerned with security, but I dont know much about it yet. Interested though.

 

[BSim500]

Is that even possible?

Yes. I have a "vanilla" i5-3570 that's a theoretical 77w but even with a mild OC + mild undervolt, it uses about 50-55w in practise due to having a low vcore (0.976v OC'd to 3.8-4.0GHz or 0.888v @ stock 3.4GHz). That's load not idle. 1x Coolermaster 212 EVO + 1x silent case fan both at 600-700rpm + a Seasonic G360, and it's virtually inaudible even from 1m away. I thought about going "all passive" but to me that last 2-3db wasn't worth a +30c increase in temps that often occurs under load (especially constant load).

- One thing with passive rigs - you need to think about some ventilation in totally passive rigs for the other components (ie, you don't want your HDD's to keep temp-cycling up to 50c and back potentially increasing the risk of drive failure). CPU fans also cool not just the CPU but motherboard VRM's around the CPU socket, etc, that can also get hot in all passive rigs.

- Seasonic X400FL are great silent PSU's.

- WD Red's have been found to be the quietest HDD's (both acoustic & vibration). All sorts of tricks like "suspension mounting" it in a 5.25" bay with elastic / bungee cord can eliminate any vibrations.

- Aluminum cases vibrate more than steel.

- Your best bet for advice is SPCR (Silent PC Review). They do a LOT of proper testing of components in a specially built anechoic chamber, focus a lot on low rpm fans / passive components, and their "decibels emitted" figures are about the only useful ones on the web. They also measure quite a bit (acoustic, vibration, air resonance, electronic noise (coil whine / capacitor squealing, etc)). Best site on the net for that stuff. May even be some people in a similar situation (music / audio production related) over on the forums there.

- 120mm fans fixed at 600rpm can be extremely quiet (single digit decibels) and can add a lot to lower temps / long-term reliability of rigs that are under heavy constant load. Bigger fans are not always quieter, you need to look at specific fan models (especially at SPCR above).

Is the 4790 a more reliable chip then a 4790S in any way?

Not more reliable (anything that's unreliable is faulty). The real key to a silent & cool CPU though is undervolting, but you can easily turn a regular chip into an "S" just by playing around with the SpeedStep settings in Windows:-

Control Panel -> Power Options -> Change Plan Settings -> Change advanced Power settings -> Processor Power Management -> Maximum Processor State

Setting it to 90% underclocks & undervolts it (on mine) to 3GHz @ barely 0.8v load which is something like 35-40w, which is between a T and S chip. It's safer than manually undervolting for important work (though you can "go extreme" and undervolt it on top). Don't take these figures as exact though as each chip varies due to the silicone lottery.

Good luck!

 

[Quad5Ny]

If your running a Z series board, you can usually set a custom TDP in the UEFI.

ASUS Example:
[Note these values are only valid if LLC is disabled and VccIN is set to default; usualy 1.8V. Also not that you can adjust the iGPU TDP if you have that enabled.]
4770K Default:
• Long Duration Package Power Limit: 84 (Stock TDP, In watts. MB will throttle multiplier('s) down if it exceeds this value-Core/Cache/iGPU)
• Package Power Time Window: 8 (Time period allowed to use Max TDP, In seconds)
• Short Duration Package Power Limit: 105 (Max allowed TDP, In watts. MB will throttle multiplier('s) down if it exceeds this value-Core/Cache/iGPU)
• CPU Integrated VR Current Limit: 95 (Max current the FIVR can draw in AMPs, MB will throttle multiplier('s) down if it exceeds this value-Core/Cache/iGPU)

4790K Default:
• Long Duration Package Power Limit: 88
• Package Power Time Window: 8
• Short Duration Package Power Limit: 110
• CPU Integrated VR Current Limit: 105

P.S. Almost all Boards have stupid power settings set by default. You need to go through the UEFI and change them to more sane settings to get maximum power savings (after going through everything I was able to save 27.8 watts while Idle). -- I'll post my UEFI settings if your interested.

P.P.S. Windows is a bit better than the UEFI if you stick with the Balanced power plan but you still need to change a few things (if you need help with this let me know as well):
1.) Enable 'HIPM+DIPM' for Drives
2.) Set Hard disk burst ignore time to '1' for Drives
3.) Set PCI Express Link State Power Management to use 'Maximum Power Savings'
4.) Go through Device Manager and Check/Uncheck 'Allow the computer to turn off this device to save power' depending on how you use the devices.