I don't have much hardware I wish I'd never bought, but I do have a few. Usually just outright redundancies rather than anything actually wrong with them, though.

To list:
- ASUS ROG Radeon RX 570 -- I don't think this is a bad card, but having paid $215 for it last year was an act of poor foresight. Really, pretty much everything I bought for my modern build besides the case, a Rosewill Line-M, which were discontinued and mine was one of the last ones they still had.
- PowerBook G4 1.5 -- Not a bad laptop, but I would get a 1.67GHz DLSD that has DDR2 and a higher res screen (1280x854 vs 1440x960) only a few months later.
- iBook G4 1.42 -- Same deal as above, kinda just superannuated by the DLSD. All three have 7447As.
- Power Mac G4 dual 800 -- This one was kind of excessive, pretty much just a guinea pig to see how far it can be upgraded. I don't actually need it though when I have both single 450 and dual 450 towers, too.
- MacBook2,1 -- I only bought it to try out libreboot, but it got in the way of getting a 1GHz A1025. It now has power supply issues.
- EVGA e-GeForce FX 5200 -- I scammed myself out of $20. I thought it was an MX 4000.
- 1GB worth of PC120 278-pin ECCREG. It's hilarious, but useless to me.
- GeForce2 MX (Apple) -- I would end up getting one with the PMG4 dual 800 anyway, and this one is broken.
- Radeon 9200 SE -- I didn't know about the SEs being nerfed cards, and was only vaguely aware of the 9200s being kinda bad themselves. It also needed PC-Mac flashing.
- Compaq MV920 -- I don't regret the monitor itself, but it caused a big fight that ended with me having my bank account drained of all my savings. Plus, .25mm dot pitch isn't amazing. I wish I had gone with a Gateway VX900 instead -- the monitor I'm eventually going to get to pair up with it in dual monitor 2880x1080 goodness.

A few pieces of hardware I wish I hadn't bought:

1) iPad 2 that came with a bundle of Apple hardware, such as a MacBook early 2015, iPad Mini, AirPort Extreme Wireless N (not bad and it's being used as a time capsule box with a 480GB SSD connected via SATA to USB) - the iPad has issues from display glitches to charger/data port issues
2) ASUS CN60 Chromebox - runs on a slow Celeron CPU, which is utter shit and DDR3L RAM is very expensive these days and I'm too lazy to upgrade it, however, it runs Linux to a point
3) PCS computer containing a 386 motherboard - lots of battery leakage that made part of the case go rusty and the screw holes for the panel won't line up properly and to make things worse, the screws never stay screwed in. I saved the board and it's working fine, however, the PSU needs to be replaced or repaired and it's a 286 system now
4) PowerBook G4 1.5 DDR - this came with the Apple hardware above and it has dings and other items. The battery is totally shot, however, the system runs fine and it's not that bad.
5) IBM PS/2 Model 25 - it runs okay, however, it has a few flaws, such as no RTC, only 1 ISA slot (or 2, I cannot recall), and it has broken plastic above the monitor that got there somehow (not damaged via transit)
6) Goldstar GVT-9100M VCR/TV combo - it only plays SP tapes and nothing else, otherwise, it'll either run too fast or too slow. No way to fix it since the VCR is basically a cheap piece of garbage, however, it does have an A/V input for connecting a better VCR. The screen portion has issues with a purple hue in a small spot at the bottom due to a magnetic interference somewhere

Since this got revived, I guess this is another forum where I talk about the Toshiba Satellite L750 laptop I bought 11 years ago. At least I missed the Intel chipset bug (early Sandy Bridge), but every single part of that laptop either performed horribly or failed unusually quickly.

The CPU was a low-end Core i3-2330M. It benchmarks better than every Core 2 Duo, but performs worse than most of them in real software. For some reason, saying that really upsets people. I eventually found one other person who mentioned strangely poor performance on a different laptop with an i7 from the same generation.

The Intel integrated graphics had totally broken drivers. Most software I tried wouldn't allow hardware acceleration to be enabled, despite meeting the minimum requirements on paper. It also gave random BSODs while using hardware H.264 decoding. Intel didn't release an updated driver for four years, and then they silently put the new driver on their website (but not Windows Update - I had to watch the list of updates to make sure Windows didn't "update" to the broken driver that the laptop shipped with because hiding an update in Windows 7 just meant "install silently a few months from now without the user's knowledge"). Then they put a bunch more "older" drivers on their website that definitely weren't there on their claimed release dates. The latest driver was more stable, but 3D acceleration was still broken. I guess I should have spent the extra money on a discrete GPU, but I didn't have that much money.

The 1366x768 display was already unusable due to its low resolution (and partially because it was a glossy panel) when it was new, but the only way to get a usable resolution on a laptop at the time was to either get a workstation or a 17" screen. It also had horrible black levels (more like light gray at minimum brightness) and the worst color quality of any color LCD I've ever seen.

Sequential read/write speeds for the hard drive dropped over time (down to 50MB/s), but the drive performed as expected in a different computer.

The keyboard failed after three months while only using it for school (not heavy typing).

The touchpad had an unusually low pointer speed, and no touch features worked (not even tap-to-click or edge scrolling - tapping would just make the cursor move slightly, and the edge scrolling region was about 1mm wide), and it was just a lightly textured patch on the palmrest with no well-defined border.

This was probably the only new computer in late 2011 with only USB 2.0 ports. There was an unpopulated footprint on the motherboard for a USB 3.0 controller that was covered with black tape. The USB ports became loose unusually quickly, and I had to regularly clean them because even external mice would become unreliable (including random movement and clicks, which I didn't think was possible for a flaky USB connection). What eventually made me get rid of this laptop was a USB 2.0 composite/S-Video capture device producing garbage frames without high CPU or disk activity and transfer rates to an external hard drive dropping to 15MB/s at the same time.

The built-in speakers were barely audible in a quiet room at full volume and eventually stopped working entirely. When the speakers stopped working, the audio codec (which had a built-in amplifier) got hot enough to make a warm spot on the outer case. Headphones still worked until the jack failed with no stress (nobody yanked on the cable).

The RAM failed after four months (not Toshiba's fault), and it took months to get it replaced under warranty. Toshiba wouldn't accept it back until I reinstalled Windows (claiming that errors in Memtest86 meant that Windows files were corrupt), and then they would replace one random part and send it back to me without testing. On the first repair attempt, they even claimed that they fixed a problem that I wasn't having. Eventually, they sent it to an authorized repair center instead of their own repair center. That other repair center made it stable, but they also did something that cut the battery life in half. Reinstalling Windows increased battery life a little, but it didn't get all the way back to normal.

I'm probably missing something here, and this post is already really long. I used this thing until 4GB of RAM wasn't enough to run Firefox (the "quantum" releases), and when I upgraded, I was told that this pile would be just as good as any new computer if I just put an SSD in it. That was the shortest amount of time I've ever kept a computer, and it was only because I didn't have the money to upgrade for that long. I kept it around for video capture until the USB failure I mentioned above. Then I got a ThinkPad P53. I did regret buying that for a while, but the only laptops I found that looked like what I wanted (for example, the AMD version of the ThinkPad L15) were only sold in Europe.

I regret buying a GF6600GT at the time it was new, I imported it from the US and it fried a few months after, then I purchased another one and the new one also fried a few months after. Gave up and ended up with a radeon 9600xt.
Years later I found out the issue was on the apartment's electrical installation... in that specific room, once anyone used the elevator, there was a huge power surge. My PSUs never lasted more than a few months and I never understood why.

Mitsumi CR 2600 TE
SyQuest SQ3270S

Celeron 300 (non A).

Ended up selling it and getting a 300A instead.

Initially got a Celeron 266 as a placeholder, but had to exchange it due to bad L1 cache. They only had the 300 in stock so had "upgrade" to that.

TBH, the 300 did run well, even at 450, but it wasn't an 300A .

I had somewhat limited means at the time and my Pentium 166MMX was getting quite long in the tooth, so I decided to get a 440BX board ( BX6 ) and the lowest cost CPU I could get for it with the expectation of upgrading later.

I probably should have just waited for the 300A, which had already been announced by that point, but I was impatient.

- ASUS Xonar DG. I bought it to replace the noisy onboard sound chip but it was just as noisy with the ASUS. That was the last sound card I bought.
- My first prebuilt PC my parents bought me for Christmas in 1999 with 433 Celeron, 64 MB and a S3Trio3D. It cost like $950 and I didn't know much about computers, just the fact that I wanted to play Quake 3. When I tried to play it came with the "Couldn't load opengl subsystem" nightmare text. Instant nosebleed moment. Got a TNT2 M64 a few weeks later and happiness ensued but I'll forever remember the S3 trauma. (and the fact that it was an extremely overpriced system sold FOR GAMING).
- Used Voodoo 1 from a shady guy on "Craigslist". Of course it was faulty but I was a kid and trusted everyone. That quickly changed.
- A huge batch of 478 P4 CPUs that had nearly EVERY SINGLE pins bent or broken. We're talking about 80 CPUs, 70 of them were useless. I managed to straighten 10 but it was a waste of time/money. No more CPU batches without pin photos for this guy.
- Not really a classic computer but Xiaomi Redmi Note 9 Pro. It was a gift but MIUI was so bad with it's crappy (lack of) notifications and stability that we became instant enemies. My wife meant well but I hated that phone with a passion. I've read through hundreds of comments from different people with the same problem and never got a solution other than getting a custom ROM. Xiaomi also actively blocked unlock with the mandatory waiting period/account/4G access. Never again.

interesting to read. i don't think i have such regrets as i only get things free or cheap for vintage tech, however i did get some old late 2000's bare bones desktops a while back with some idea of doing something, and now they just sit there taking up room. I had mentally planned to buy nothing more thinking (probably accurately) that what i had is already enough for any uses i may ever have. Maybe in the end i'll use them, but they are a reminder that apparently cheap 'bargains', even if the price is very low, doesn't mean you should get it!

New PSU's that don't have enough watts and amps on the 5v rail to handle old machines like Athlon XP's. They don't make them like they used to! Lately my go-to has been finding new old stock PC Power & Computing power supplies from mid 2000's.

-Enermax power supply because it was supposedly a good brand, but no, it was full of shitty capacitors that lasted only six moths
-GF6800GT, GF8800GTS, GF8800GTX, GF8800 Ultra, Vaio laptop with an GF8400GT, CLEVO laptop with a GF6600go and two Asus M2n-sli, at the time I was young and never thought it could be because Nvidia started to make shitty hardware with the release of the GF6000 series, and they are never responsible for anything, so a lot of money lost because of Nvidia and a lot of trash thanks to then.
That was my own hardware, not counting all the hardware by Nvidia I've seen dead at the sales and repairs shop where I worked.
-Asus P5LD2, I still have it and use it in one computer, a great board by Asus but with one big lie by Intel, 4 GB or more ram supported but the 945p chipset can't properly work with the 4gb RAM it leaves only around 3GBs to use, and that's a chipset that support a lot of x64 CPUs by intel.
-One Alienware M17x R3 with a Radeon HD6990m, the GPU cooler can't hold half the TDP of the 6990m, so it was a matter of time to see the GPU fail, even the CPU cooler can't maintain the turbo clocks for more than one second and there's an overclocking option in the BIOS, that makes me laugh or cry, it depends on if the day is rainy or sunny.
I won't buy any kind of expensive hardware again, it is like the most you pay the worst hardware you get and the most expensive is something more affected is by the programmed obsolescence.

Edit, I'm sure I'm forgetting something. 😀

Multiple IBM Thinkpad A31p machines.

I find these fascinating, since you can put a 2.6GHz Pentium 4 in them and they come with a sexy 1600x1200 IPS panel and great Windows 98SE + DOS drivers (including SoundBlaster support).

Every single one I bought had problems from the start or developed them later on. The panels tend to get weird spots after many years (or the CCFLs burn out), the RAM slots are of poor quality so you frequently need to resolder them, the machines run insanely hot on the fastest CPU's, they are massively heavy, the GPU runs too hot and develops the usual problems of BGA chips losing connection...

The machine I currently own still "works", but it started to draw much more power than usual which eventually leads to the power supply overheating and shutting off. I suspect some component on the board developed a short...
I swore to myself that I won't buy any more of these. Spec-wise they're insanely cool, but SO unreliable.

I put the nicest IPS panel into my A22p and this one is much more stable. Although the A2x series have their own problems with a specific chip on the board.
Seems like IBM had real problems with their massive workstation machines back in the day, almost any of them has a problem that's not trivial to fix.

In their times:
A complete assembled new K6-2 350 machine simply too much expensive.

A brand new Voodoo3 2000 AGP for the machine above simply too much expensive.

Retro computers.
I have run out of storage room for this stuff but I can’t stop from buying it.

This GeForce FX 5700LE.

Despite actually having a 128-bit memory bus (rare for the LE varieties) it's only as fast as a GeForce 3 Ti200. This particular card also doesn't like to be overclocked and is relatively noisy. Worst of all, it cannot use 45.23 drivers, even with a modded INF file, and needs a driver from the 5x.xx line. Sadly, those drivers are not compatible with certain Win9x era genes like Thief 2.

On the plus side, the card was only 10 EUR, so there's that. It might be more suitable for someone else's use case, but not mine.

Gateway motherboard with 440BX chipset.

Mine was very disappointing. The ISA slot it had didn't work properly with any sound card I installed and occasionally it refused to POST.

Creative Labs ISA sound cards.

It's my own fault for not researching the various issues that plague Creative Labs cards (particularly noise), but I wound up with at least a few CL ISA cards (AWE32 and a couple SB Pros) that I probably wouldn't buy again.

As low-noise / clean output is a priority for me, I always end up using a non-Creative Labs card in my various retro builds.

I suppose I can at least do some comparison recordings for YouTube or something. But beyond that, I don't see myself using Creative Labs cards in my retro systems.

Shponglefan wrote on 2022-11-26, 20:48:

It's my own fault for not researching the various issues that plague Creative Labs cards (particularly noise), but I wound up with at least a few CL ISA cards (AWE32 and a couple SB Pros) that I probably wouldn't buy again.

My first Creative Labs sound card was a CT3600 SB32 PnP. This is one of the cheaper SB (AWE)32 models, most notably, it doesn't have an original OPL3. When I connected proper headphones instead of some old AM-radio level stuff to it, I did encounter serious noise problems, but that could easily be fixed by adjusting the mixer: There is some analog noise floor in the mixer that gets amplified by the "master volume" setting. So setting "music" and "voice" to a low level and "master" to a high level produces an unacceptable amount of noise, but setting "music" and "noise" high, and "master" low produces a signal that is good enough for most purposes.

Shponglefan wrote on 2022-11-26, 20:48:

Creative Labs ISA sound cards. […]
Show full quote

Creative Labs ISA sound cards.

It's my own fault for not researching the various issues that plague Creative Labs cards (particularly noise), but I wound up with at least a few CL ISA cards (AWE32 and a couple SB Pros) that I probably wouldn't buy again.

As low-noise / clean output is a priority for me, I always end up using a non-Creative Labs card in my various retro builds.

I suppose I can at least do some comparison recordings for YouTube or something. But beyond that, I don't see myself using Creative Labs cards in my retro systems.

I'd be interested in hearing the comparisons if you make them!

mkarcher wrote on 2022-11-26, 20:56:

My first Creative Labs sound card was a CT3600 SB32 PnP. This is one of the cheaper SB (AWE)32 models, most notably, it doesn't have an original OPL3. When I connected proper headphones instead of some old AM-radio level stuff to it, I did encounter serious noise problems, but that could easily be fixed by adjusting the mixer: There is some analog noise floor in the mixer that gets amplified by the "master volume" setting. So setting "music" and "voice" to a low level and "master" to a high level produces an unacceptable amount of noise, but setting "music" and "noise" high, and "master" low produces a signal that is good enough for most purposes.

In my case, I have the CT2760 which purportedly has an earlier, noisier DAC. I admittedly haven't tried mucking around with mixer settings yet, so I may give that a shot at some point.

In the mean time, all my DOS builds usually end up with some combination of GUS + ESS + Roland hardware. It's been serving me well.

Ensign Nemo wrote on 2022-11-26, 21:19:

I'd be interested in hearing the comparisons if you make them!

If/when I get around to building an audio test bench system, I will certainly post them.

I've got about 40-50 sound cards at this point, so I suppose I should do something with them. 😁