Intel Core Solo ULV U1500 socket: Socket 479

What the Core Solo ULV U1500 is

The Core Solo ULV U1500 closed out the single-core ULV Yonah line in January 2007. Its one 65 nm Yonah core reaches 1.33 GHz, the highest clock Intel offered in the 5.5 W Solo envelope. One thread comes from that single core, backed by 2 MB of L2 cache and the familiar 533 MT/s front side bus. Machines built around it were late-era thin notebooks that prized silence and battery time over raw throughput.

A locked 10x multiplier sets the 1.33 GHz mark against the 533 MT/s bus. No turbo state exists, so thermal planning deals with one known ceiling rather than a burst range. Enhanced Intel SpeedStep still steps the clock down at idle, which matters in a chassis with a small fan or none at all. Instruction support matches the Yonah family: MMX, SSE, SSE2 and SSE3 with 32-bit addressing only, leaving 64-bit operating systems off the table.

Holding 5.5 W at 1.33 GHz made the U1500 the efficiency pick of its season. Board makers could reuse the slim thermal parts drawn up for the U1300 and U1400, since the package and power class stayed constant. The Micro-FCBGA 479 chip solders directly to the board through 479 balls, and a maker spreader carries heat away from the die. Owners never handle the processor itself; they service the fan, the vents and the thermal interface.

The U1500 makes most sense beside its two predecessors. It outpaces the 1.07 GHz U1300 and the 1.2 GHz U1400 while drawing the same rated power, though real battery gains depend on the chassis and screen. Dual-core ULV Yonah parts at 9 W offered a second thread for multitasking at the price of a larger power budget. Single-threaded chores of the day, such as office documents and local media, suited the U1500 well.

Socket and motherboard compatibility

The U1500 is soldered to its board and cannot be replaced, so the board is the compatible unit, not the chip. Its ball package bonds to a Napa platform board from the Intel 945 chipset family during manufacture. Only firmware written for that exact board knows the part, and only the maker support list can confirm a donor. The Socket vs chipset: what decides whether a CPU works guide walks through those maker checks for mobile hardware.

That fixed Socket 479 package stands apart from the socketed Yonah family under Socket M. Socket M machines accept pinned Core Solo and Core Duo T series chips that lift out with a hinge and a BIOS entry. This U1500 has no pins, no hinge and no BIOS swap path. Mixing the two lines is impossible at the board level, so a failed U1500 board needs a board built for the same soldered part.

Because the three Solo ULV numbers share a package and power class, paperwork must be read closely. Clocks run 1.07, 1.2 and 1.33 GHz across the U1300, U1400 and U1500 with 8x, 9x and 10x multipliers, and firmware tables follow those numbers. Match the service code on the board before ordering anything. A board tuned for a slower sibling would misreport and mismanage the faster chip.

Memory, PCIe and cooling

Memory reaches the U1500 through the board chipset alone. Makers fitted DDR2 on the Intel 945 based Napa platform, choosing slot counts and module limits per chassis. The CPU side runs at 533 MT/s across the front side bus, which governs how fast cache misses resolve into main memory. Approved DDR2 modules in the maker specified sizes keep that path free of errors, and two equal sticks suit boards wired for pairs.

Expansion also belongs to the chipset. The processor exports no PCI Express lanes; its single external link is the front side bus into the 945 chip, and every slot, port and wireless card connects past that point. Graphics sit in the chipset or in a discrete mobile GPU on the board, never in the Yonah die. Upgrading the hard disk to a newer drive or adding memory changes the feel of these machines more than the 1.33 GHz clock suggests.

Cooling fits the 5.5 W class. A thin plate or short pipe joins the soldered package to the exhaust, tuned by firmware that expects exactly this power curve. There is no packaged cooler and no clamp pattern to shop for. When an old machine runs hot, the cause is usually blocked vents or tired paste between spreader and pipe, both corrected with ordinary cleaning and new interface material.

Upgrade paths

The U1500 offers no processor upgrade. Its 479 solder balls fix it to one board forever, and no workshop procedure changes that. Even the slower U1300 and U1400 cannot donate or receive this chip. The Intel Celeron 220 page repeats the same verdict for its own soldered Socket 479 package, since the limitation comes from the package, not the brand name.

Anyone wanting more speed must replace the board with one built for a quicker soldered Yonah, or retire the machine for a newer used notebook. Buyers who value swap options should instead hunt socketed Yonah systems under Socket M, where pinned T series chips move within the maker list. The Socket vs chipset: what decides whether a CPU works guide covers how to verify either path before money changes hands.