PCI-Express 3.0 / 4.0 - Chipset Z390 / Z490

All previous pages described processors and their chipsets. Way is so important to change this components every few years? Simple, better performance of PC, to get faster and efficient business especially when is some trouble like COVID-19. Also games looks nicely then before. As main components of PC is microprocessor and graphic card and their possibilities, what chipset have with that? What is main purpose of chipset? The following could be determined.

Chipset is a set of electronic components in an integrated circuit known as a 'Data Flow Management System' that manages the data flow between the processor, memory and peripherals. Chipset acts like the motherboard’s communications center and traffic controller. Because it controls communications between the processor and external devices, the chipset plays a crucial role in in computer system performance.
Every motherboard contains several different types of buses, which can vary in terms of speed and bandwidth, but for simplicity’s sake, we can break them down into two groups:
- External buses - Also named 'Expansion buses' for devices connected over USB, serial, and parallel ports.
- Internal buses - Like PCI-express, system bus or busses for slots on the motherboard, and memory bus etc.
Over time, the performance of the buses has changed in line with the development of technology, as shown in the Figure 3.5.7.
The primary internal bus found on modern motherboards is known as PCI Express (PCIe). PCIe utilizes 'lanes', which allow internal components such as RAM and expansion cards to communicate with the CPU and vice versa. A lane is simply two pairs of wired connections; one pair sends data, the other receives data. So, a 1x PCIe lane will consist of four wires, 2x has eight, and so forth, as shown in the table at the beginning of this chapter 3.5.10. More corridors means more bandwidth through the connector or the possibility of more connected graphics cards. More corridors means more bandwidth through the connector or the possibility of more graphics cards connected. Thus, serial data transmission through a single corridor, with synchronized parallel transmission for multiple corridors.
The main role of the new chipsets is to enable higher communication speeds between devices via PCI, PCI-Express (PCIe), SATA, USB, Bluetooth, Ethernet, Wi‑Fi, optical and other communication technologies. As these technologies advance in data rate, they must be accompanied by the development of chipsets. This essentially allows the advancement of integrated circuit technology - lithographic process in order to make as few transistors as possible, and combining as many transistors into a single group - integrated circuit, to fulfill as many logical requirements. The small silicon wafer advances daily in its capabilities making the lithographic process finer. It is also important to maintain compatibility with the slower standards from their inception. For example, compatibility between versions USB-v1 to USB-v4, PCIe-v1 to PCIe-v5 and the like.
Typically, integrate functions of chipset is: clock generator, bus controllers, system timer, interrupt controller, DMA controller, CMOS/RAM clock, keyboard controller, mouse controller etc.

PCIe evolution Where is now, for example, PCI-Express 4.0 standard? SSDs is the first PCIe-v4.0 devices which come to market for PCs. Because the PCIe-v4.0 bus specification was finalized after a lot of delays by years, we ended up with a situation where the PCIe-v5.0 bus specification was finalized only a couple of years later after PCIe-v4.0 standard. The PCI-SIG group recently published the 0.9 version of the PCIe-v5.0 specification, and we should see support for it in computing products soon. How soon? PCIe-v5.0 standard is currently available, but will be commercially available for another few years or more.
Maybe in this moment it is not necessary to use motherboard with PCIe-v4.0 bus support, and devices without it. Maybe this moment will be very short? So, motherboard with PCIe-v4.0 bus support is not necessary bad choice in this moment. When such motherboards exists, manufactures of PC components will react quickly. I believe that many things about peripheral devices of PC toward to PCIe-V4.0 bus will be changed since to end of the year 2020, especially at end of the year 2021. Santa Claus is always full of surprises.

The basic concept of chipset and microprocessor are shown in the following example in version for desktop PC.

Example XV

In this example shown in the block diagram of the chipset z390 and z490. Shown in the example motherboard supports Core i3, Core i5, Core i7 and Core i9 microprocessors of ninth generation planned with the socket LGA 1151v2 and tenth generation planned with the socket LGA 1200.

Processor
Processors codenamed 'Coffee Lake' and 'Comet Lake' are based on improved 14 nm technology (14++).
Difference between 9th and 10th generation of high-end 'desktop' processors are:

Intel® Core microprocessors
Product Name	Core i9 9900K	Core i9 9900KF	Core i3 9350K	Core i9 10900K	Core i9 10900KF	Core i3 10320
Code Name	Coffee Lake			Comet Lake
Chipset	series 3XX			series 4XX
Essentials
Lithography	14 nm			14 nm
PCIe support	3.0			3.0 (4.0)
Socket	LGA 1151v2*			LGA 1200*
Performance
# of Cores	8	8	4	10	10	4
# of Threads	16	16	4	20	20	8
Base Frequency	3.6 GHz	3.6 GHz	4.0 GHz	3.7 GHz	3.7 GHz	3.8 GHz
Turbo Frequency	5.0 GHz	5.0 GHz	4.6 GHz	5.3 GHz	5.3 GHz	4.6 GHz
Smart Cache	16 MB	16 MB	8 MB	20 MB	20 MB	8 MB
Bus Speed	8 GT/s DMI3
TDP	95 W		91 W	125 W		65 W
Memory Specifications
Max Size	128 GB		64 GB	128 GB
Memory Types	DDR4 - 2666		DDR4 - 2400	DDR4 - 2933		DDR4 - 2666
# of Channels	2			2
Bandwidth	41.6 GB/s		37.5 GB/s	45.8 GB/s		41.6 GB/s
ECC Support	No	No	Yes	No	No	No
Graphics Specifications
Processor Graphics	UHD 630	No	UHD 630	UHD 630	No	UHD 630
* The socket LGA 1151v2 and LGA 1200 is physically the same but number of connectors (pins) is not same and have different electrical functions. They are not electronically compatible.

Z390 / Z490 - Platform Controller Hub (PCH)
Main chip of chipset is PCH and other chips are his assistance. Chipset is a link to an external PC devices (I / O Controller Hub), a basic feature of the chipset and support for processors manufactured in enhanced 14 nm technology for LGA 1151v2 and LGA 1200 package. Lithography of chipset is in 22 nm technology. The following Figures shows the block-schema of Z390 and Z490 chipset.

Figure* 3.5.47 Block-diagram of z490-z390 chipset. ( + / - )

As usual, with Intel new line of chipsets goes with its new processors. With that new motherboards are required. That is not exclusive rule because on motherboard can be use with any processor from actual generation. New generation of processors do not necessarily need new motherboard. With BIOS upgrade (microcode) it is possible to use processors of next generation if they are electrically compatible. By upgrading the BIOS, the 'Z490' chipset and 'z490 gaming X' motherboard will support the 11th generation of Intel microprocessors and it will be nice if the 12th generation is included. Therefore, the motherboard must be the work of a reputable manufacturer with good BIOS support.

Figure* 3.5.48 GIBABYTE 'z490 gaming X' and 'z390 gaming X' motherboard. ( + / - )

Motherboards looks great. This motherboard is design for one graphic card and quite a lot of other type of PCIe peripherals. Typical for users with other needs regarding by other type of devices that can be inserted into slots. Therefore, motherboard have 3xPCIe-x1, 1xPCIe-x4 (physically x16) and 1xPCIe-x16 slots. A useful feature of the design is the reinforced metal-armor slots for the x16 slot and two memory slots to prevent the motherboard from bending due to heat and to make safe contact with the inserted devices. Of particular joy are the three slots for SSDs and compatibility with the PCIe-v4.0 interface that should arrive with the next generation LGA 1200 processors. Multi-functional motherboard. Of course gamers will preferred design with more 1xPCIe-x16 slots.

A description with yellow letters, as in the previous illustrations, is not necessary because everything that is needed is written on the motherboard.

The connectors on the rear side of the motherboard are physically similar. The connections shown in Figure 5.3.49 refer to the motherboard GIBABYTE 'z490 gaming X'. At the motherboard is implemented 'M.2 SATA SSD' and 'M.2 PCIe SSD' connectors. That is reason for use z490 chipset, because speed toward SSD via SATA is to slow. The possibility of using this type of 'disk' was introduced with the z170 chipset (Figure 3.5.42b). The following Figure shows one of the modules of this type.


Figure 3.5.49 Module of 'M.2 PCI SSD' class.

HDD, SSHD or SATA-SSD become 'bottleneck' for functionality of whole PC system. 'M.2 PCIe SSD' at PCIe-V4.0 now exists as device and can be of great importance in terms of PC system performance. The data transfer speed can be up to 10 times higher than previous solutions. Some series of this motherboard have implementing Wi‑Fi possibilities, therefore at rear connector plate is implemented two SMA Antenna Connectors. If classic Ethernet is available and PC with big case (no something like notebook), Wi‑Fi is not necessary. Wi‑Fi is security hole in the system. The desktop computer is a member of the SOHO network anyway. The SOHO network router most likely has better Wi‑Fi security mechanisms.


Figure 3.5.50 Connectors at 'z490 gaming X' motherboard.

Insight into the possibility of connectors on the back of the motherboard, and possibly added connectors that have connectors on the motherboard, everything is significantly improved in terms of communication speed between devices. Of course, compatibility with slower devices is supported. The only thing that hasn't changed is the USB standard for keyboard and mouse, because these are communication-friendly devices anyway. It is good to have a PS/2 connector in terms of direct communication with the motherboard without the involvement of the operating system. Looking forward to a stable and efficient built-in NIC.

SUMMARY:

What should the end user do? I will not go into the policies of various companies but will express my opinions for my home computer. The processor I use is a Core i5-7600K, and the cheapest replacement with a 10th generation microprocessor is the Core i3-10320. In the overall performance score, the 10th generation 'leads' by approximately 15%. When the possibilities come true one can always take one Core i9. The Core i9 series processors are a novelty in the 'Core' series of microprocessors; Core i3, Core i5, Core i7 and Core i9. More offers for the user, so let him take what he can. My choice between the two motherboards described goes in favor of the Z490 version as it allows for the connection of much faster peripherals compared to the Z170 I am currently using. Little by little, everything will be replaced with better ones, and you give away or sell 'old' devices. After all, why opt for a technology that is about to end.

As for the chipset with support for PCIe-v4.0, it is now in a 'breakthrough' on the market and device manufacturers are adapting to it, and I believe that in a couple of years it is possible that PCIe-v5.0 will be 'skipped' to PCIe-v6.0. It all depends on the progress of technology, i.e. on the available lithographic process when making integrated circuits. Maybe Santa Claus will think a little, and change his mind and give users 10 generation Intel processors that support the PCIe-v4.0 standard, anyway for a feint and a joke.