Rent Out Your Idle GPU: What a 4090 Clears Each Month

Not fixed income. Under one assumption set — 600W rig, power ¥0.32/hr, list price $0.20/hr, fee assumed 20%, 1 USD = ¥7.1 — a 4090 clears about ¥588 at 100% uptime (720 hours/month), about ¥176 at 30%. Home machines look like the second number.

Scenario table: monthly net left over, by list price and uptime

One set drives the table: 600W rig; power about ¥0.32/hr; fee assumed 20% (not a published SpareHive rate); 1 USD = ¥7.1 (planning rate, not board rate); 720 hours/month as 100% uptime. $0.20 and $0.25 are hypothetical list prices, not offers.

01. Renting out an idle GPU — what's actually left each month?

Start with the 30% row: about ¥176.

List price $0.20/hr, fee at an assumed 20%. Thirty percent uptime roughly means taking jobs evenings and weekends — hours the machine was on anyway, when you weren't gaming. ¥176 covers a gaming rig's power bill with a little left over. That is the whole claim.

¥588 is the same assumptions at 720 full hours.

Use it as a ceiling, not an expectation. 100% uptime means the machine rents for 24 hours a day, 30 days a month: case never opened, never gamed on, never offline, never rebooted. Your home hits none of those, so treat none of them as given.

SpareHive dispatches no jobs today and has published no rates.

This table is not a payout record. SpareHive is still registering hosts; neither list prices nor the fee are published. Every number here exists to show how the math works, not to report anyone's earnings.

02. How does ¥176 get carved out of $0.20?

$0.20 minus the assumed 20% leaves the host $0.16.

Fee comes off first: 20% of $0.20 is $0.04, so the host side nets $0.16/hr. Power isn't subtracted yet.

A 600W rig costs about ¥0.32/hr in power.

The tariff input is residential ¥0.532/kWh; a 600W rig draws 0.6 kWh per hour. If your city's rate differs, multiply your own per-kWh price by 0.6, replace ¥0.32, and run the table again — every row drops in expensive-power cities.

Net of power at ¥7.1/USD, a full hour clears about ¥0.82 — about ¥588 over 720 hours.

The body of this article reuses that result rather than re-converting at another rate. $0.16 minus roughly ¥0.32 of power leaves about ¥0.82 — the net left over from each hour that truly rents — and 720 of those hours sum to the ceiling.

03. Why would anyone pay more than your power bill?

Overseas renters pay a $0.49/hr median for a 4090 on Vast.ai.

The $0.14 floor is one machine; the median is the number renters actually budget. A home card listed at $0.20–$0.25 undercuts that median by roughly 50%–60% — which is why a renter would look twice. That is the premise the whole business rests on.

The same 600W rig costs about $0.047/hr in power in China, versus $0.10–$0.22 in the US or Europe.

The power gap is structural — it is not "you will definitely get rentals." An overseas host's power bill alone eats $0.10–$0.22, so their listing price cannot come down; yours, at $0.047, can. That is the host side's only edge, and the entire edge.

$0.20–$0.25 is a planned list-price range; SpareHive pricing is not set.

The range sits about 50%–60% under the $0.49 median and is written down so the math has an input. It is not an offer, not a promise, and not a transacted price.

04. Where do the uptime numbers come from, and who decides?

10%, 30%, 50%, and 100% are assumption rows, not platform statistics.

There are no rental records yet, so any "average uptime" would be invented. The four rows exist so you can pick the one that matches your home: a machine that is always on anyway, look higher; evenings only, look at 10% and 30%.

The hours you take back to game count as zero.

Hosts can pause anytime and grab the card back to play. Pausing carries no penalty, but paused hours earn nothing either — run the math that way, instead of murmuring ¥588 while you game.

List only for hours you were on anyway, then read the 10% row: about ¥59 or ¥79.

Those two cells exist to break the "leave it running and collect ¥588" fantasy: net of power it is tens of yuan — bubble tea money, not rent money. Treat it as a power subsidy and your expectation is calibrated.

05. What do running platforms actually pay hosts?

Salad's 4090 tier starts at $0.16/hr, paid mostly as gift-card balance.

Balance is not cash. It buys games and subscriptions; it does not pay the utility company, which takes money only. When you see "$0.16 and up" listed, check the settlement method before installing anyone's client.

Clore.ai lists about 20,000 cards, takes a 1.8%–10% commission, and adds token subsidies.

The commission is genuinely low, but the subsidy is a token. Token prices move; this article does not forecast them, and your scenario table should not contain a token-forecast row either.

Domestic cloud vendors in China rent 4090s from about ¥1.32/hr.

That is a datacenter cloud, not your home broadband line. One of them lists ¥1.86/hr with 150 free hours and 200+ prebuilt images — datacenter power, operations, and staffing are a different business from a card under your desk. Don't benchmark your machine against a datacenter price, and don't let one scare you off either.

06. Which cards and which jobs make it into this table?

The table is computed for a 4090 in a 600W rig.

A 3090 or 5090 does not map onto ¥588. Different card, different draw, different jobs — swap the card and you swap the inputs, so recompute honestly.

The jobs are image and video work from small overseas teams.

Still images and short clips — the work that grows out of the demand side. No mining; this article does not discuss mining, the table above has no mining row, and it never will.

By design the host makes outbound-only connections; home broadband without a public IP works.

This is a design note, not network debugging done on your behalf. The machine dials out, so no port forwarding is needed, and homes behind carrier-grade NAT (CGNAT) can join. To register, go to register your idle GPU; for what gets installed, how data is wiped, and what happens on disconnect, read is renting out your GPU safe first.

FAQ

Can a rented 4090 really make ¥588 a month?

Only if every assumption in the table holds at once and the machine rents all 720 hours — about ¥588. At 30% uptime, about ¥176. That is not a SpareHive payment promise.

Does the platform take 20%?

No rate is published today. The 20% is this table's assumption, used to see what remains after power.

If the machine is on while I'm not gaming, does that count as 100%?

No. 100% means 30 days × 24 hours. Subtract every hour you shut down, pause, or drop offline, and read the 10% or 30% row instead.

Can I list without a public IP?

SpareHive's design dials out from the machine, so no public IP is required at home. Today is host registration only; no jobs are being dispatched yet.

Can I mine while listing?

No. This math covers image and video jobs only. The platform design does not accept mining.