The name in the search box is 4000. Intel does not sell a Core Ultra 4000. Its public names for this run of chips are Series 1, Series 2, and Series 3. The leak that lines up with the search is Core Ultra 400, which the same slides call Series 4 and which partners call Nova Lake. Desktop and laptop are both in the rumor, and they are not known to the same standard.

Intel has said one sentence that matters, and that sentence is not a specification. HotHardware's account of the January 2026 earnings call quotes chief executive Lip-Bu Tan saying next-generation Nova Lake was "coming at the end of 2026." He did not name a socket, a core count, a wattage, or a model number. Intel's desktop collection page, reviewed in March 2026, still ends at Series 2, the processors formerly called Arrow Lake. That page includes a first-quarter 2026 Plus refresh, the 270K Plus and the 250K Plus, and those parts keep 200-series numbers on the same LGA 1851 socket as the chips from 2024. Intel's laptop comparison chart runs from Series 1 through Series 3 and has no Series 4 column. Series 3 arrived at CES in January 2026 as a laptop. Intel calls it the first client processor with a compute tile on Intel 18A. The datasheet also lists N6 and N3E tiles in the package, so 18A is not the whole chip. There is no Series 3 desktop in Intel's collection.

The three series you can already buy are different machines, which is why the table splits Series 2. Series 1 was Meteor Lake, in laptops from December 2023, on Intel 4, with up to 16 cores in a 6 performance, 8 efficiency, and 2 low-power mix. It was the first client chip with an NPU, about 11 TOPS, inside a platform total of about 34. Series 2 is where the lineup split in two. The thin laptop, Lunar Lake, reached stores on September 24, 2024: eight cores, memory on the package, up to 32 GB of LPDDR5X-8533, and an NPU Intel rated at up to 48 TOPS inside a platform total of up to 120. The desktop, Arrow Lake, followed on October 24, 2024. Intel's current support page lists up to 24 cores and 24 threads, so the extra thread per performance core is gone, on a new LGA 1851 board with an 800-series chipset. The unlocked parts are 125 W at the base and up to 250 W in turbo. Memory is DDR5, up to 256 GB, at DDR5-6400 on the Core Ultra 9 285K and DDR5-7200 on the Plus refresh. The desktop NPU on that support page is 13 TOPS. Series 3 is Panther Lake, and it is a laptop. Intel's chart for the Core Ultra X9 388H lists 16 cores as 4 performance, 8 efficiency, and 4 low-power, a 5.1 GHz turbo, 18 MB of cache, a 25 W base, LPDDR5X-9600, up to 96 GB, and Arc B390 graphics with up to 12 Xe cores. Launch reporting put the NPU at up to 50 TOPS. Desktop buyers stayed on Series 2.

The fourth column is a stack of leaks. A slide posted by @wxnod on September 3, 2026, written up by Tom's Hardware and by Wccftech, says Nova Lake-S enters mass production in the fourth quarter of 2026, that the first chip into stores is a 28-core desktop in the first quarter of 2027, and that a 52-core part follows later that year. The slide names a new LGA 1954 socket, 900-series boards, and a large last-level cache, called bLLC, of up to 288 MB on the dual-tile chip. Earlier notes put 144 MB on a single compute tile. The sentence about matching AMD's 3D V-Cache is the slide's own claim, and it is not a test result. Tan's "end of 2026" can live next to a first-quarter retail date if the factories start in the fourth quarter. Intel has not confirmed either date for a named processor. Tom's Hardware's reading of the wider leaks is up to 16 Coyote Cove performance cores, 32 Arctic Wolf efficiency cores, and four low-power cores on that range-topping part.

An October 2026 list, published by VideoCardz, puts seven desktop names under the 4000 label. The Core Ultra 9 4970K BFC is printed as 8 performance cores, 16 efficiency cores, and 4 low-power cores, 28 in total, at 125 W, with the large cache and a 32-execution-unit graphics block. The next row does not add up. The Core Ultra 9 4950K is shown as 8+16+4 and also as 24 cores, while the article text says the listing does not show those four low-power cores. Other writeups of the same post split the same way. BFC is not a suffix Intel has defined. The rows that carry it are the ones marked with the large cache. The 52-core chip is absent from this list of seven. Trust the 4970K split, which adds up, and do not treat a printed total that fights its own columns as a specification.

Partner material reported in April 2026 describes the same generation with DDR5-8000, an NPU 6, and two Xe3 graphics cores on the desktop dies it listed. That two-core note and the October list's 32 execution units are different documents. This piece does not weld them into one graphics specification, and it does not invent a TOPS number for NPU 6. Power figures far above the listed 125 W show up in other writeups. They are not in the September slide Tom's Hardware printed, so they are left out. Intel has not said which factory builds this compute tile.

The laptop rumor is a certification record, not a calendar. On September 30, 2026, TechPowerUp reported that the USB Implementers Forum lists Nova Lake-H device IDs D331 and D333 for USB4, plus a desktop chipset ID, 6E6E, for USB 3.2. A compliance listing does not give a ship month or a core count. An older report, from May 2026, had mobile Nova Lake possibly on stage at CES in January 2027 with up to 28 cores. The later desktop slide puts the first retail chip on the desktop instead. The laptop month is not settled, and Intel has not published one.

Keep a second 2027 rumor out of this column. Reporting on Gigabyte firmware has described processors for next year that still take DDR4, on the old LGA 1700 socket, which points at a Raptor Lake follow-on. That follow-on is not Core Ultra 400, and it should not be filed as one. If the Nova Lake leaks hold, a 400-series desktop needs a 900-series board. It does not fit the Series 2 machine on a desk today, and it does not fit a board from the DDR4 years either.

Read across the four columns and the change is the socket, then the cache, then which computer gets the generation. Series 1 put an NPU in a laptop and left the desktop behind. Series 2 put on-package memory and a fast NPU in a thin laptop, and gave the desktop a new board with a small NPU and one thread per core. Series 3 is the 18A laptop, and the desktop never received it. Series 4, in the leaks, is another new desktop socket, the first of these generations to put low-power cores on a desktop package, with a 28-core 125 W part in front and a 52-core cache chip behind it. None of that last column is a product row on intel.com.

The split that matters is between a sentence Intel did say and a stack of slides it did not. Nova Lake at the end of 2026 is Tan's line. LGA 1954, the 4970K BFC, 125 W, DDR5-8000, and 288 MB are the leaks, and those leaks disagree with themselves on the 4950K. Until a Core Ultra 400 part shows up on Intel's list, the desktop to plan around is still Series 2 on LGA 1851, and the laptop on 18A is Series 3.