I do not think this would be smart, as far as I read in my few days 'research' about this.
All 75W GPUs have specification for 300W PSU or more and I have seen many of them!
HP800 G1 with 240W is made only for 35W GPUs as far as I know (and even then there is not much reserve just in case).
240W PSU does not really give you 100% efficiency on average, 240W is just the peak.
How much could I really expect my PSU to give is a question, I read that it might be about 75%,
so that could be just 180W....
i5 CPU should take 75W, SSD 10W (and I might add one more which is then 20W), 20W 4x4GB GENESIS DDR3 RAM,
Motherboard 20W, and GPU 75W (if not more?)=about 220W already!!! It's already past those 180W, and too close those 240W too!!!
Plus peaks could be higher, so there should be some reserve-JUST IN CASE and not to worry about it while enjoying a game.
So in intensive games for GPU, I could have blue screens, freezes, I could damage my components (motherboard, CPU,...)
or even burn my whole house (heheheh). I do not want to have any risk of any of these, I want 0% risk as compared to now
when I only have integrated GPU.
I read online that I could put in HP GPU 320W, this would be the max possible power I could get in HP800G1 SFF.
I do not know which model of GPU is that, but if I really added it (however probably to put this money somewhere else),
then I would be able to get in GTX 1650 and similar as you suggest.
First off, do you have two separate threads on this subject? That's really confusing - don't double post unless you want to confuse the people helping you.
Secondly: there is quite a bit that's off in the quoted text above. I'll go through it point by point so that you can get a clearer picture of your needs and options. Sorry if this turns into a novella-like chunk of text - I tend to overexplain. Still, more information = better choices
1:
240W PSU does not really give you 100% efficiency on average, 240W is just the peak.
What you're talking about here isn't efficiency, but the rated power output (and how it can differ from the marketing name). This point really has three parts, so I'll go through each:
1.1: (Power conversion) Efficiency is the amount of waste heat produced by a power supply when converting a given amount of power, but this does not affect the output power - lower efficiency increases
input power (how much it "draws from the wall") but the output power is not affected by efficiency, just how much power is wasted as heat while providing the output. In other words, a 240W PSU should always output 240W - but it'll create a lot more heat doing so if it's rated at 75% efficiency than if it's rated at 95% efficiency. The difference is that the 75% efficient unit will draw 320W from the wall when outputting 240W while the 95% efficient unit will only draw 253W. All power above 240W is waste heat that the PSU has to dissipate, so the PSU fan on the less efficient unit will have to run faster, and it'll still be likely to fail earlier.
1.2: PC PSUs are rated for continuous power, not peak. AFAIK, the ATX spec (which all standard PC PSUs must meet) requires ratings to be for continuous output power (though don't quote me on that - it is the norm, at least). Peak output power is usually higher (though not always!), but also not particularly safe (and often quite inefficient). The heatsinks/fan are also usually not designed for dissipating more heat than required at 100% load. In other words, a 500W PSU should be able to output 500W "for ever" (every PSU will
eventually die, but it should take a few years), but might also be capable of handling 600W short-term loads - this depends on the design and quality of the PSU, though. Bad quality PSUs might claim a higher rating than they really have, but that is rarely a problem in established markets these days (it was quite common 10-15 years ago). Most serious PSU reviewers test overload conditions both to see how the PSU handles them and if/when overcurrent protection (OCP) kicks in.
1.3: Not all ratings are equal. PC PSUs supply several voltages, and the output of these are normally added up for the rated wattage. Modern PCs almost exclusively load the 12V rail under normal use (which is why modern high-end PSUs can often deliver their entire rated output on that one rail), which means that older design PSUs where the 12V rail is disproportionately weak (PCs used to use 3.3V and 5V a lot more back in the day) can underperform. I have an old PSU lying around that exemplifies this beautifully:
It's nominally rated at 400W, but the 12V rail is only rated at 15A, or 180W. The 400W rating is in fact rounded up from 380W when combining the rated outputs of the 5V, 3,3V and 12V rails.
In other words: check the label on your PSU for its +12V output rating. That's the most important number for a modern system. I mentioned to you in another thread that I'm doing a similar project in a Dell Optiplex 990 SFF, and its 240W PSU has a maximum 12V output of 200W.
2: Your power consumption calculations are way too high. A normal SSD does
not use 10W of power (the very hottest m.2 NVMe SSDs can reach 7-8 under peak power draw, most are half that or less, and under normal usage in the 1-2W range if not even lower, while enterprise-grade HHHL PCIe SSDs might exceed 10W). SATA SSDs generally use less power than NVMe drives, and rarely exceed 2W under the heaviest loads. SSDs in consumer use cases spend the vast majority of their time idle, in which case they barely use power at all. 4 DDR3 RAM sticks do not consume 20W either, and the motherboard certainly doesn't consume 20W on its own. A far more sensible calculation is 5W per SSD for NVMe drives and slightly more than 5W per two SSDs for SATA drives, and somewhere between 15 and 30W for the motherboard and RAM combined, depending on the system (higher powered CPUs cause higher VRM losses as there's more power converted from 12V to the CPU's required voltage, but VRM losses for standard, <95W CPUs are negligible). For a non-K i5 system with 4 RAM sticks I'd say 20W is a generous allotment for the motherboard and RAM. For reference,
here's a server setup where they measured the difference between 4 and 16 sticks of DDR4 to be a scant 27W. DDR4 is lower power than DDR3, but not by more than 20-30%, so if 12 sticks of DDR4 consume 27W, 4 sticks of DDR3 shouldn't exceed 10W, and outside of the VRM the only "major" power draw will be any fans connected to the motherboard, and most PC fans consume very little power, many are below 1W.
3: Just like online PSU calculators, GPU manufacturers' "PSU requirement" specs are utter bollocks. They are generally based on worst-case scenarios simply because there's no way for the GPU maker to know what other components you have in your PC or what quality your PSU is - so they go way overboard just to be safe (and avoid frivolous lawsuits in regions where that's a thing). A 75W GPU might spike to 85W for a few milliseconds, but loads that short are of no importance unless your PSU is utter garbage. (Also, GPUs without external power connectors tend to control their power draw quite strictly as pulling more power through the motherboard slot might fry the motherboard.) Still, read detailed reviews for
actual power consumption numbers (as they will always vary), and combine that with measurements of your other equipment. If you look around these forums, you'll find a lot of people running 75W GPUs off <200W internal DC-DC PSUs.
An example: My Optiplex peaked around 130W measured at the wall (i.e. including the losses from heat in the PSU as well as the entire rest of the system) running Prime95 on the CPU with no GPU installed. IIRC that rose to about 135W with a low-profile Radeon HD 5450 in there under the same load, and by another 10W or so if I also fired up FurMark. The CPU peaked at 75-80W according to HWMonitor, which isn't entirely reliable, but gives a decent ballpark number for internal CPU power draw. From that, I calculated that I should be safe(-ish) adding a ~100W GPU in there, which I was hoping I could undervolt my RX 570 to reach. In reality, gaming loads don't stress the CPU near as much as Prime95, and I'm able to run my RX 570 at stock clocks while staying under the 200W 12V output of the PSU. I've measured ~265W at the wall while playing Rocket League, which sounds scary high until you factor in that this (terrible!) PSU has an average efficiency of just 65%, meaning that a 265W wall power reading translates to somewhere around 175W internally. This is of course not entirely accurate (efficiency isn't linear, but varies with the output of the PSU, so in theory efficiency could be higher at this load, which would mean I'm closer to the max output than I think). Now, I'm pushing the limits of this build, and I'm very conscious of doing so - this is a hobby project, not my main PC.
Nonetheless, this demonstrates that a "95W CPU" (i5-2400) and 150W GPU (RX 570) don't necessarily translate to 245W power draw under normal usage. A 75W GPU would be
well within the capabilities of a PSU like this - including yours, unless there's something
really weird about how it's configured. You're right that it's smart to leave some overhead in your PSU rating (20-30% is a good number), but base that off real-world power consumption, not on-paper numbers, as those are often complete fiction.
Your main limitations here are as follows:
-Space: How big a GPU can you fit? Low-profile? Full height? Single or double slot? The manual seems to say LP only, but unless you have lots of other AICs there's plenty of room for a dual-slot card.
-Power: I assume your PSU has no PCIe power plugs, so you're limited to motherboard power. That means 75W, though many OEM SFF systems spec their PCIe slots lower. I can't find anything about this
in the manual for your PC, so 75W might be fine, but there's not really any way of knowing without trying.
-Budget: How much can you/do you want to spend on this? If I were you, I'd order a GTX 1050 if you can afford it, and return it if it for some reason shouldn't work. It'll cost you slightly more than a 1030, but the performance difference is massive, and no matter what it'll be cheaper than the 1650 LP cards whenever they arrive.
Sorry for going on and on here, but hopefully this brings you a bit closer to figuring things out. A 1030 GDDR5 will likely be a perfectly fine GPU, but its value is
terrible, and the 1050 is a lot better. An RX 550 might also be a good in-between solution, at ~25% faster than the 1030, but the 1050 is again >50% faster than the 550. All of them ought to work.
Btw, here's a YouTube video of someone recommending a 1050 for use in that PC (at least that's the card linked in the description, the GPU they're installing is not a 1050). Whichever one you choose, it'll likely be good, and it's sure to be a lot better than the iGPU
