question about TDP (computer components)

[dsayers]

Short version of my question: If I was running identical software on two computers whose only difference was that one had a video card rated at 60 TDP and the other one's was rated at 150 TDP, would the 150 TDP machine be running hotter because the video card was in fact stronger or would it run cooler because I'd be utilizing a lower percentage of its capabilities? Since TDP is not universally determined, I wanted to include that the cards in question were of the same line by the same manufacturer (though different generation).

 

 

Long version: The last time I rebuilt my PC, I hand picked components that were relatively low power to achieve low heat, to make the use of quieter AIR cooling solutions more realistic. I was very pleased with the results, which included a power supply whose fan never needs to come on, thermistor controlled case fans that almost never need to come on, and a fanless, gaming class video card (Radeon HD 7750 by Sapphire, which had replaced me fanless Radeon HD 4670 by Sapphire).

 

I've been considering upgrading the video card. My pursuit for fanless models has been a frustrating one despite nVidia's release of Maxwell architecture at the beginning of this year making it a more realistic option than ever. I have found a GTX750Ti by Palit. However, Palit doesn't sell to the US. Also, Amazon.co.uk says they cannot ship it to the US, even though they can ship the non-Ti version to the US despite it having identical shipping weight/dimensions!? I've been in contact with them to figure out which item was the erroneously classified one.

 

When I revised my criteria from fanless to quiet, I was pointed in the direction of Asus's Strix series, which has a robust pipe/heatsink system AND fans that will only come on when necessary. I think I'm willing to give this a try and want to do what I can to make sure those fans are off as much as possible because what other PCers/gamers consider to be quiet is rather annoying to me. Case in point, my only continuous fan right now is on the processor, and it is a 600-700 RPM model. I can hear that it's on, but usually ambient drowns it out well enough.

 

Anyways, within the Strix line, I'm currently eyeballing their GTX750Ti and the "newly" released GTX970. The 750Ti would be a significant step up for me as it is. The 970 is significantly stronger still. It has newer tech and would generally be better from a future-proofing standpoint (such as that is with PC components). What gives me pause (besides the price tags) is that their TDP ratings are substantially different. Namely 60W and 145W respectively.

 

At first glance, I was ready to abandon the 970 for price and TDP alone. However, I got to thinking that because the 970 is significantly stronger, would this mean that what I use it for would make it cooler, leaving the fans off more often? If so, it might be worth the extra expense for the extra quiet. Or is it like comparing an 8 cylinder engine to a 4 cylinder in that it would consume more juice (produce more heat) in idle as a result of it being stronger?

 

For what it's worth, I very rarely do video editing. Beyond that, the most intensive thing I use my PC for is playing Skyrim, which my current video card handles just fine on medium settings with numerous mods installed.

[HordOfTheFlies]

The quoted wattage values are for peak load scenarios.  Most likely both cards use very low power at idle (10W max) so for normal desktop operation you should never hear the fans.  The question is how sensitive is each card to heat build-up under load.  The 970 over doubles the capacity of the 750Ti in terms of max power usage so that means it's also capable of generating over twice as much heat at the same rate.  This will be balanced by the cooling system on the card, however.

 

I know that doesn't give you an answer, but that's because those numbers are meaningless by themselves.  I couldn't find any benchmarks or I would refer you to them.  If you want good numbers I'd be looking at idle wattage and wattage under various loads (watching a video, gaming, etc).  You would probably also want to look at heat dissipation numbers between the specific cards if those are provided.  That might give you an overall sense of how efficiently the cards work.

 

All that being said, my gut says that you probably won't go wrong with either.  I just can't see a 970 having the fans switch on any more than a 750Ti under any condition.  The biggest drawback is that the 970 will cost you more money initially as well as in electricity over time.  But the eye candy...

[MrCapitalism]

I have a gigabyte GTX 760 and the GPU fans run continuously even when I'm only using the browser or the  machine is idling. If that helps putting your plans into perspective.

[dsayers]

Thanks for the responses. I am aware that TDP alone isn't enough. It's just one of the two factors that gave me pause with the 970. One that I later thought to myself actually might mean cooler card at same usage. I too don't think that either card would be problematic. It's just I've never spent that much on a video card and never chased after top of the line since I'm not big into action gaming and prefer gameplay over eye candy. That said, the 970 is technically stunning and being newly released would last a whole lot longer technologically speaking.

[shirgall]

The 750Ti in particular is the latest generation chipset from nvidia, and uses considerably less power at idle and at full power than a similarly capable device of the previous generation. You are right that TDP all by itself doesn't tell enough of the story, but I can attest that at idle it's pretty mellow. I got my 750Ti from EVGA.

 

Check out this article from Tom's Hardware: http://www.tomshardware.com/reviews/geforce-gtx-750-ti-review,3750-21.html

[dsayers]

The 970s are Maxwell too. When I found out that the Palit wasn't going to be acquire-able in the US (still baffles me), I thought maybe I'd wait for the proper Maxwell roll-out. Then later found that that time was nigh.

 

I had been asking around and found somebody that says that negligible overhead aside, the stronger card will typically run cooler below capacity than weaker cards doing the same thing.

 

The funny part is that this led to me deciding to get the 970 only to find that everyplace I could order it from (newegg, amazaon, microcenter) were out of stock. Amazon even had a back in stock date on their site a couple days ago that isn't there anymore. And I kid you not that newegg went from being out of stock when I first checked to in stock when I went to see if I could determine a restock date.

 

So that order has been placed! I'll report back with my findings. I don't think it's going to be a problem though since my 7750 was good enough and the 970 is going to be at least 3 times stronger.

[cynicist]

I know this is late but just to clarify a bit:

 

At idle, they will be identical as far as noise and power consumption. At load (gaming), the noise levels of the two cards are within 2db of each other, which is pretty insignificant. The major difference between them is the power consumption at load, where the GTX 750 ti averages 178 watts¹ and the GTX 970 averages 313 watts², a difference of 57%. So unless you desire the increased performance to run new games at high settings, basically required only if you are running multiple monitors or high resolutions or just like to max out quality settings, you are better off with the lower power bill. Given that everyone who owns a computer spends most of their time idle anyway, it's not hugely important though. What makes the 750 ti awesome is how small it is, enabling you to create a great small form factor build that isn't useless for gaming or has heat problems.

 

Sources: [1] http://techreport.com/review/27203/geforce-gtx-970-cards-from-msi-and-asus-reviewed/5

[2] http://techreport.com/review/26050/nvidia-geforce-gtx-750-ti-maxwell-graphics-processor/10

 

Also, TDP is the thermal envelope for regular operation of a component, not max power. It stands for Thermal Design Power. So a higher TDP always correlates to higher heat under load since that is what is being measured. (That's how they determine what cooling is adequate)

[MrCapitalism]

If you don't need a strong graphics solution, and you want to minimize the number of noise producing fans... have you considered going with one of Intel's K processors that has a GPU on the chip?

[dsayers]

Do you mean i processors? I thought Intel's K just indicated unlocked multiplier for OCing purposes. Which I don't get into at all. In fact, the first thing I'm going to do when my Strix arrives is see if I can run it at reference frequency instead of their "factory overclock" just to cool it down a bit more.

 

I do need some form of graphics capability. My laptop has a Haswell (4th gen) i7 as its GPU. It can run Reckoning alright, but only got like 3 FPS in Dishonored. It's just that my graphics needs aren't as high as most people who would call themselves gamers since I'm not as interested in visuals.

 

Thanks for the info, Mr. Rak. Had I seen that before, it might've steered me into the 750Ti. I think the main reason I was so amenable to the 970 is because I'm already rocking an i7-4770 with 32GB of RAM and 500 GB SSD as primary drive. Also, I do dabble in video rendering from time to time, which modern softwares can make use of your GPU to accelerate. As long as the 970 doesn't double as a skillet, I'll be set for quite some time.

[MrCapitalism]

you're right, it's the "i" series.

[dsayers]

Thought I'd provide an update. The GTX970 is silent most of the time, even in Skyrim on the highest settings. The only time they come on is during video editing. It's made video editing that much smoother, so I'm really glad I went with the stronger card.